Method of detection of IL1RAP on cells expressing the protein

Abstract

The present invention provides an antibody or an antigen-binding fragment thereof with binding specificity for human interleukin-1 receptor accessory protein (IL1RAP) wherein the antibody or antigen-binding fragment is capable of inhibiting to domain 3 of human IL1RAP. The invention further provides the use of such antibodies or an antigen-binding fragments in the treatment and/or diagnosis of cancers, such as leukemias and melanoma.

Description

This application is a divisional of U.S. application Ser. No. 15/501,710, filed on Feb. 3, 2017, which is a 371 application of international application no. PCT/EP2015/068208, which was filed on Aug. 6, 2015, and claims priority to United Kingdom application no. GB 1413913.3, which was filed on Aug. 6, 2014, all of which are incorporated by reference in their entirety.

FIELD OF INVENTION

The present invention relates to antibody-based agents for the treatment and diagnosis of diseases and conditions associated with an IL-1 biomarker (specifically, IL1RAP) and/or responsive to inhibition of IL-1 signaling. In particular, there are provided antibody-based agents for the treatment and diagnosis of cancers, including but not limited to leukemias (such as chronic myeloid leukemia, acute myeloid leukemia, acute lymphoblastic leukemia, myeloproliferative disorders and myelodysplastic syndrome) and cancers associated with solid tumour formation (such as melanoma, lung cancer, and breast cancer).

BACKGROUND

Interleukin-1 Biology

Interleukin-1 (IL-1) is a potent pro-inflammatory cytokine that can be produced by a variety of cell types, including mononuclear phagocytes, in response to infection and inflammation. The IL-1 family consists of seven agonists, including IL-1α and IL-1β, and three naturally occurring receptor antagonists, including the IL-1 receptor antagonist (IL-1Ra) (Dinarello, C A, Blood 1996, 87(6): 2095-147). Two IL-1 receptors, IL-1R type I and IL-1R type II, have been identified. Both receptors can interact with all three forms of the IL-1 family molecules. IL-1RI is responsible for mediating IL-1-induced cellular activation. However, the IL-1/IL-1RI complex cannot signal by itself, but is dependent on association with a second receptor chain, IL-1R Accessory Protein (IL1RAP) (Dinarello, C A, Blood 1996, 87(6): 2095-147). In contrast to IL-1RI, IL-1RII does not induce cellular activation upon binding to IL-1 and thus IL-1RII functions as regulatory decoy receptor, leading to a net decrease in IL-1 available to bind to IL-1RI.

In addition to IL1-signaling, IL1RAP is critical for mediating the effects of IL-33, through the ST2/IL1RAP complex, and IL36, through the IL1Rrp2/IL1RAP complex (Garlanda et al., Immunity. 2013 Dec. 12; 39(6):1003-18)

IL-1 is a potent pro-inflammatory cytokine, which is induced at sites of local infection or inflammation and is involved in the regulation of a variety of physiological and cellular events (summarised in Dinarello C A, CHEST, 2000, 118: 503-508 and Dinarello, C A, Clin Exp Rheumatol, 2002, 20(5 Suppl 27): S1-13). It is capable of activating several cell types including leukocytes and endothelial cells. IL-1 induces and amplifies immunological responses by promoting the production and expression of adhesion molecules, cytokines, chemokines and other inflammatory mediators such as prostaglandin E₂ and nitric oxide (NO). As a consequence, local inflammation is amplified and sustained. In addition, the IL-1-induced production of inflammatory mediators results in fever, headache, hypotension and weight loss. Furthermore, IL-1 is a hematopoietic growth factor and has been shown to reduce the nadir of leukocytes and platelets in patients during bone marrow transplantation. IL-1 has also been shown to promote angiogenesis by inducing the production of vascular endothelial growth factor, thereby promoting pannus formation and blood supply in rheumatic joints. Finally, IL-1 has been shown to promote the bone and cartilage degradation in rheumatic diseases.

The Role of IL-1 in Disease

IL-1 is implicated in a wide range of diseases and conditions ranging from gout to cancer (for reviews, see Dinarello et al., 2012, Nature Reviews 11:633-652 and Dinarello, 2014, Mol. Med. 20(suppl. 1):S43-S58; the disclosures of which are incorporated herein by reference), including:

• • Joint, bone and muscle diseases, such as rheumatoid arthritis and osteoarthritis;
  • Hereditary systemic autoinflammatory diseases, such as familial Mediterranean fever;
  • Systemic autoinflammatory diseases, such as systemic juvenile idiopathic arthritis and adult-onset Still's disease;
  • Common inflammatory diseases, such as gout and type 2 diabetes;
  • Acute-onset ischemic diseases, such as myocardial infarction; and
  • Cancer.

A number of therapies for blocking IL-1 activity are approved and in development. Targeting IL-1 began in 1993 with the introduction of anakinra (Kineret; Amgen), a recombinant form of the naturally occurring IL-1 receptor antagonist (IL-Ra), which blocks the activity of both IL-1α and IL-1β; this therapeutic has since been used to demonstrate a role for IL-1 in numerous diseases (see above). Anakinra currently dominates the field of IL-1 therapeutics owing to its good safety record, short half-life and multiple routes of administration. Neutralising IL-1 with antibodies or soluble receptors has also proved to be effective, and the soluble decoy receptor rilonacept (Arcalyst; Regeneron) and the anti-IL-1β neutralizing monoclonal antibody canakinumab (Hans; Novartis) have now been approved for certain rare genetic conditions, such cryopyrin-associated periodic syndromes (CAPS). Other therapeutic approaches, including IL-1α neutralisation, a therapeutic vaccine targeting IL-1β and a chimaeric IL-1Ra, are in early clinical trials. In addition, orally active small-molecule inhibitors of IL-1 production, such as caspase 1 inhibitors, have been developed and are being tested.

Interleukin-33 (IL-33) is a nuclear-associated cytokine of the IL-1 family. IL-33 signals via the receptor IL-33R (ST2) and plays an important role in allergy, asthma, infections, inflammation, and in promoting cancer growth (see Cayrol & Girard (2014) Curr Opin Immunol. 31:31-7 and Maywald et al. (2015) PNAS 112(19):E2487-2496). IL1RAP is critical part of the IL-33R (ST2) receptor complex to convey the signals by IL-33 (see Chackerian et al. (2007) J Immunol. 179(4):2551-2555).

IL1RAP as a Biomarker for Neoplastic Disorders

Tumour biomarkers are endogenous proteins or metabolites whose amounts or modifications are indicative of tumour state, progression characteristics, and response to therapies. They are present in tumour tissues or body fluids and encompass a wide variety of molecules, including transcription factors, cell surface receptors, and secreted proteins.

Effective tumour markers are in great demand since they have the potential to reduce cancer mortality rates by facilitating diagnosis of cancers at early stages and by helping to individualize treatments. During the last decade, improved understanding of carcinogenesis and tumour progression has revealed a large number of potential tumour markers. It is predicted that even more will be discovered in the near future with the application of current technologies such as tissue microarrays, antibody arrays, and mass spectrometry.

Interleukin-1 receptor accessory protein (IL1RAP) has previously been identified as cell-surface biomarker associated with haematological neoplastic disorders such as chronic myeloid leukemia (CML), acute myeloid leukemia (AML) and myelodysplatic syndromes (MDS) (for example, see WO 2011/021014 to Cantargia A B, Järås et al., 2010, Proc Natl Acad Sci USA 107(37):16280-5, Askmyr et al., 2013, Blood. 121(18):3709-13 and Barreyro et al., 2012, Blood 120(6):1290-8, the disclosures of which are incorporated herein by reference). More recently, the usefulness of IL1RAP as a diagnostic and therapeutic biomarker for solid tumours, such as melanomas, has also been revealed (see WO 2012/098407 to Cantargia AB, the disclosures of which are incorporated herein by reference).

SUMMARY OF INVENTION

The present inventors have developed new anti-IL1RAP antibodies with improved properties making them suitable for diagnosis and treatment of diseases and conditions associated with the IL1RAP biomarker and/or responsive to inhibition of IL-1 signaling, IL-33 signaling and/or IL-36 signaling.

Accordingly, in a first aspect, the present invention provides an antibody or an antigen-binding fragment thereof (‘antibody polypeptides’) with binding specificity for domain 3 of interleukin-1 receptor accessory protein (‘IL1RAP’).

By “interleukin-1 receptor accessory protein”, “IL1RAP” and “IL1-RAP” we specifically include the human IL1RAP protein, for example as described in GenBank Accession No. AAB84059, NCBI Reference Sequence: NP_002173.1 and UniProtKB/Swiss-Prot Accession No. Q9NPH3-1 (see also Huang et al., 1997, Proc. Natl. Acad. Sci. USA. 94 (24), 12829-12832, the disclosures of which are incorporated herein by reference). IL1RAP is also known in the scientific literature as IL1R3, C3orf13, FLJ37788, IL-1RAcP and EG3556.

By “domain 3” of IL1RAP we include the structural region defined by amino acids 235 to 369 of IL1RAP according to numbering used in Accession No. Q9NPH3 of UniProtKB/Swiss-Prot (see also Wang et al., 2010, Nature Immunology, 11:905-912, the disclosures of which are incorporated herein by reference). For example, the epitope to which the antibody or antigen-binding fragment binds may be located within amino acids 235 to 239, 240 to 249, 250 to 259, 260 to 269, 270 to 279, 280 to 289, 290 to 299, 300 to 309, 310 to 319, 320 to 329, 330 to 229, 240 to 349, 350 to 359 or between amino acids 360 to 369 of IL1RAP.

Thus, the antibody polypeptides of the invention have specificity for IL1RAP. By “specificity” we mean that the antibody polypeptide is capable of binding to IL1RAP in vivo, i.e. under the physiological conditions in which IL1RAP exists within the human body. Preferably, the antibody polypeptide does not bind to any other protein in vivo. Such binding specificity may be determined by methods well known in the art, such as ELISA, immunohistochemistry, immunoprecipitation, Western blots and flow cytometry using transfected cells expressing IL1RAP. Advantageously, the antibody polypeptide is capable of binding selectively to IL1RAP, i.e. it bind at least 10-fold more strongly to IL1RAP than to any other proteins.

By “an antibody or an antigen-binding fragment thereof” we include substantially intact antibody molecules, as well as chimaeric antibodies, humanised antibodies, isolated human antibodies, single chain antibodies, bispecific antibodies, antibody heavy chains, antibody light chains, homodimers and heterodimers of antibody heavy and/or light chains, and antigen-binding fragments and derivatives of the same. Suitable antigen-binding fragments and derivatives include Fv fragments (e.g. single chain Fv and disulphide-bonded Fv), Fab-like fragments (e.g. Fab fragments, Fab′ fragments and F(ab)₂ fragments), single variable domains (e.g. V_H and V_L domains) and domain antibodies (dAbs, including single and dual formats [i.e. dAb-linker-dAb]). The potential advantages of using antibody fragments, rather than whole antibodies, are several-fold. The smaller size of the fragments may lead to improved pharmacological properties, such as better penetration of solid tissue. Moreover, antigen-binding fragments such as Fab, Fv, ScFv and dAb antibody fragments can be expressed in and secreted from E. coli, thus allowing the facile production of large amounts of the said fragments.

Thus, in one embodiment, the antibody polypeptide of the invention comprises or consists of an intact antibody (such as an IgG1 antibody).

In an alternative embodiment, the antibody polypeptide of the invention comprises or consists of an antigen-binding fragment selected from the group consisting of Fv fragments (e.g. single chain Fv and disulphide-bonded Fv), Fab-like fragments (e.g. Fab fragments, Fab′ fragments and F(ab)₂ fragments) and domain antibodies (e.g. single V_H variable domains or V_L variable domains).

The phrase “an antibody or an antigen-binding fragment thereof” is also intended to encompass antibody mimics (for example, non-antibody scaffold structures that have a high degree of stability yet allow variability to be introduced at certain positions). Those skilled in the art of biochemistry will be familiar with many such molecules, as discussed in Gebauer & Skerra, 2009, Curr Opin Chem Biol 13(3): 245-255 (the disclosures of which are incorporated herein by reference). Exemplary antibody mimics include: affibodies (also called Trinectins; Nygren, 2008, FEBS J, 275, 2668-2676); CTLDs (also called Tetranectins; Innovations Pharmac. Technol. (2006), 27-30); adnectins (also called monobodies; Meth. Mol. Biol., 352 (2007), 95-109); anticalins (Drug Discovery Today (2005), 10, 23-33); DARPins (ankyrins; Nat. Biotechnol. (2004), 22, 575-582); avimers (Nat. Biotechnol. (2005), 23, 1556-1561); microbodies (FEBS J, (2007), 274, 86-95); peptide aptamers (Expert. Opin. Biol. Ther. (2005), 5, 783-797); Kunitz domains (J. Pharmacol. Exp. Ther. (2006) 318, 803-809); affilins (Trends. Biotechnol. (2005), 23, 514-522); affimers (Avacta Life Sciences, Wetherby, UK).

Also included within the scope of the invention are chimaeric T-cell receptors (also known as chimaeric T cell receptors, chimaeric immunoreceptors, and chimaeric antigen receptors or CARs) (see Pule et al., 2003, Cytotherapy 5(3):211-26, the disclosures of which are incorporated herein by reference). These are engineered receptors, which graft an arbitrary specificity onto an immune effector cell. Typically, CARs are used to graft the specificity of a monoclonal antibody onto a T cell; with transfer of their coding sequence facilitated by retroviral vectors. The most common form of such molecules is fusions comprising a single-chain variable fragment (scFv) derived from a monoclonal antibody fused to CD3-zeta transmembrane and endodomain. When T cells express this fusion molecule, they recognize and kill target cells that express the transferred monoclonal antibody specificity.

Persons skilled in the art will further appreciate that the invention also encompasses modified versions of antibodies and antigen-binding fragments thereof, whether existing now or in the future, e.g. modified by the covalent attachment of polyethylene glycol or another suitable polymer (see below).

Methods of generating antibodies and antibody fragments are well known in the art. For example, antibodies may be generated via any one of several methods which employ induction of in vivo production of antibody molecules, screening of immunoglobulin libraries (Orlandi. et al, 1989. Proc. Natl. Acad. Sci. U.S.A. 86:3833-3837; Winter et al., 1991, Nature 349:293-299, the disclosures of which are incorporated herein by reference) or generation of monoclonal antibody molecules by cell lines in culture. These include, but are not limited to, the hybridoma technique, the human B-cell hybridoma technique, and the Epstein-Barr virus (EBV)-hybridoma technique (Kohler et al., 1975. Nature 256:4950497; Kozbor et al., 1985. J. Immunol. Methods 81:31-42; Cote et al., 1983. Proc. Natl. Acad. Sci. USA 80:2026-2030; Cole et al., 1984. Mol. Cell. Biol. 62:109-120, the disclosures of which are incorporated herein by reference).

Suitable methods for the production of monoclonal antibodies are also disclosed in “Monoclonal Antibodies: A manual of techniques”, H Zola (CRC Press, 1988, the disclosures of which are incorporated herein by reference) and in “Monoclonal Hybridoma Antibodies: Techniques and Applications”, J G R Hurrell (CRC Press, 1982, the disclosures of which are incorporated herein by reference).

Likewise, antibody fragments can be obtained using methods well known in the art (see, for example, Harlow & Lane, 1988, “Antibodies: A Laboratory Manual”, Cold Spring Harbor Laboratory, New York, the disclosures of which are incorporated herein by reference). For example, antibody fragments according to the present invention can be prepared by proteolytic hydrolysis of the antibody or by expression in E. coli or mammalian cells (e.g. Chinese hamster ovary cell culture or other protein expression systems) of DNA encoding the fragment. Alternatively, antibody fragments can be obtained by pepsin or papain digestion of whole antibodies by conventional methods.

In one embodiment, the antibody polypeptides of the invention are defined by reference to the variable regions of a murine-derived antibody, designated ‘CAN01’, which comprises:

(a) a heavy chain variable region having the amino
acid sequence of SEQ ID NO: 1:
[SEQ ID NO: 1]
Q V Q L Q Q S G T E L M K P G A S V K I S C K A
T G Y T V S S Y W I D W V K Q T P G H G L E W I
G E I L P G S A I N N Y N E K F K G K A T F T A D
T S S N T A Y M Q L S S L T S E D S A V Y Y C A
S G D Y F D S T F V Y Y W G Q G T T L T V S S
and
(b) a light chain variable region having the amino
acid sequence of SEQ ID NO: 2:
[SEQ ID NO: 2]
D V L M T Q T P L S L P V S L G D Q A S I S C R S
S Q S I V H S N G N T Y L E W Y L Q K P G Q S P
K L L I Y K V S N R F S G V P D R F S G S G S G T
D F T L K I S R V E A E D L G V Y Y C F Q G S H V
P R T F G G G T K L E I K R

The term “amino acid” as used herein includes the standard twenty genetically-encoded amino acids and their corresponding stereoisomers in the ‘D’ form (as compared to the natural ‘L’ form), omega-amino acids other naturally-occurring amino acids, unconventional amino acids (e.g. α,α-disubstituted amino acids, N-alkyl amino acids, etc.) and chemically derivatised amino acids (see below).

When an amino acid is being specifically enumerated, such as “alanine” or “Ala” or “A”, the term refers to both L-alanine and D-alanine unless explicitly stated otherwise. Other unconventional amino acids may also be suitable components for polypeptides of the present invention, as long as the desired functional property is retained by the polypeptide. For the peptides shown, each encoded amino acid residue, where appropriate, is represented by a single letter designation, corresponding to the trivial name of the conventional amino acid.

In one embodiment, the antibody polypeptides as defined herein comprise or consist of L-amino acids.

It will be appreciated by persons skilled in the art that any intact IgG antibody comprising the above variable regions may be used as the reference antibody to identify antibody polypeptides of the invention that competitively inhibit CAN01 binding to IL1RAP.

Thus, in one embodiment, the CAN01 antibody used as a reference to determine to competitive binding is an intact IgG antibody comprising:

• • (a) a heavy chain comprising a variable domain of SEQ ID NO:1 grafted on to an murine IgG1 or IgG2a constant region; and
  • (b) a light chain comprising a variable domain of SEQ ID NO:2 grafted on to a murine kappa constant region.

Alternatively, the reference antibody may be a chimaeric, intact IgG antibody comprising:

• • (a) a heavy chain comprising a variable domain of SEQ ID NO:1 grafted on to an human IgG1 constant region (for example, such as SEQ ID NO: 30; as encoded by the pFUSEss-CHIg-hG1 vector InvivoGen, San Diego, USA); and
  • (b) a light chain comprising a variable domain of SEQ ID NO:2 grafted on to a human kappa constant region (for example, such as SEQ ID NO: 29; as encoded by the pFUSE2ss-CLIg-hk vector InvivoGen, San Diego, USA).

Suitable methods for determining whether a given test antibody is able to inhibit the binding of a reference antibody to an antigen are well known in the art. For example, to test whether a test antibody is able to inhibit the binding of the CAN01 reference antibody to a cell surface antigen, cells expressing the antigen can be pre-incubated with the test antibody for 20 min before cells are washed and incubated with the reference CAN01 antibody conjugated to a fluorophore, which can be detected by flow cytometry. If the pre-incubation with the test antibody reduces the detection of the reference CAN01 antibody in flow cytometry, the test antibody inhibits the binding of the reference antibody to the cell surface antigen.

Such competitive binding inhibition may also be determined using BIAcore chips with immobilised IL1RAP and incubating with the reference antibody (such as ‘CAN01’) with and without an antibody polypeptide to be tested. Alternatively, a pair-wise mapping approach can be used, in which the reference antibody is immobilised to the surface of the BIAcore chip, IL1RAP antigen is bound to the immobilised antibody, and then a second antibody is tested for simultaneous IL1RAP-binding ability (see ‘BIAcore Assay Handbook’, GE Healthcare Life Sciences, 29-0194-00 AA 05/2012; the disclosures of which are incorporated herein by reference).

In a further alternative, competitive binding inhibition can be determined using flow cytometry. For example, to test whether a test antibody is able to inhibit the binding of the reference antibody to a cell surface antigen, cells expressing the antigen can be pre-incubated with the test antibody for 20 min before cells are washed and incubated with the reference antibody conjugated to a fluorophore, which can be detected by flow cytometry. If the pre-incubation with the test antibody reduces the detection of the reference antibody in flow cytometry, the test antibody inhibits the binding of the reference antibody to the cell surface antigen. If the antibody to be tested exhibits high affinity for IL1RAP, then a reduced pre-incubation period may be used (or even no pre-incubation at all).

In a further alternative, competitive binding inhibition can be determined using an ELISA (e.g. as described in Example N).

Competitive binding typically arises because the test antibody binds at, or at least very close to, the epitope on the antigen to which binds the reference antibody (in this case, CAN01). However, it will be appreciated by persons skilled in the art that competitive binding may also arise by virtue of steric interference; thus, the test antibody may bind at an epitope different from that to which the reference antibody binds but may still be of sufficient size or configuration to hinder the binding of the reference antibody to the antigen.

The antibodies and antigen-binding fragments of the present invention were identified after extensive screening of a large number of anti-IL1RAP antibodies, on the basis of exhibiting properties that make them particularly suitable as diagnostic and therapeutic agents for cancer.

Thus, in one embodiment, the antibody or antigen-binding fragment exhibits one or more of the following properties:

• • (a) a binding affinity (K_D) for human IL1RAP of 2 nM or greater, i.e. the K_D≤2 nM (for example, as determined using the Biacore methodology in Example A);
  • (b) cross-reactivity with IL1RAP from Macaca fascicularis (for example, as determined in Example D);
  • (c) an inhibitory action on IL-1 signaling (for example, as determined in Example E, L and M);
  • (d) capability of inducing antibody-dependent cell-mediated cytotoxicity (ADCC) in one or more cancer cell lines (such as a CML, AML, ALL and/or melanoma cell lines, and/or cell line models of one or more of the other cancer types identified below) (for example, as determined in Examples F and G); and/or
  • (e) capability of internalisation upon binding to one or more cancer cell lines (such as a CML, AML, ALL and/or melanoma cell lines, and/or cell line models of one or more of the other cancer types identified below) (for example, as determined in Example H).

Advantageously, the antibody or antigen-binding fragment exhibits all of the above properties.

In one embodiment, the antibody or antigen-binding fragment further exhibits an inhibitory action on IL-33 signaling and/or IL-36 signaling (for example, as determined in Examples L and M below).

Optionally, the antibody or antigen-binding fragment does not exhibit an inhibitory action on one or more of IL-1 signaling, IL-33 signaling and IL-36 signaling (for example, as determined in Example E, L and M). For example, the antibody may be CAN01, which lacks any appreciable inhibitory action on IL-1 signaling or IL-33 signaling (see Examples L and M below).

In an alternative embodiment, the antibody or antigen-binding fragment exhibits one or more of properties (a), (b), (c) and (e) above, but is not capable of inducing ADCC.

In one embodiment, the antibody or antigen-binding fragment is capable of binding to an epitope on the extracellular domain of IL1RAP which overlaps, at least in part, with the epitope on IL1RAP to which reference antibody CAN01 is capable of binding. Thus, the antibody or antigen-binding fragment may be capable of binding to an epitope located at/within domain 3 of IL1RAP, i.e. amino acids 235 to 367 (see above).

In a preferred embodiment, the antibody or antigen-binding fragment thereof according to the first aspect of the invention comprises a heavy chain variable region comprising the following CDRs:

• • a) G Y T V S S Y [SEQ ID NO: 3] or an amino acid sequence having at least 60% sequence identity therewith, for example at least 70%, 80%, or 90% sequence identity;
  • b) L P G S A I [SEQ ID NO: 4] or an amino acid sequence having at least 60% sequence identity therewith, for example at least 70%, 80%, or 90% sequence identity; and
  • c) G D Y F D S T F V Y Y [SEQ ID NO: 5] or an amino acid sequence having at least 60% sequence identity therewith, for example at least 70%, 80%, or 90% sequence identity.

Thus, the antibody or antigen-binding fragment thereof may comprise a heavy chain variable region comprising the CDRs of SEQ ID NOs 3, 4 and 5.

For example, the antibody or antigen-binding fragment thereof may comprise a heavy chain variable region having the amino acid sequence of the corresponding region of the CAN01 reference antibody, i.e. SEQ ID NO:1.

However, it will be appreciated that a low level of mutation (typically, just one or two amino acids) within a CDR sequence may be tolerated without loss of the specificity of the antibody or antigen-binding fragment for IL1RAP.

Percent identity can be determined by, for example, the LALIGN program (Huang and Miller, Adv. Appl. Math. (1991) 12:337-357, the disclosures of which are incorporated herein by reference) at the Expasy facility site (http://www.ch.embnet.org/software/LALIGN_form.html) using as parameters the global alignment option, scoring matrix BLOSUM62, opening gap penalty −14, extending gap penalty −4. Alternatively, the percent sequence identity between two polypeptides may be determined using suitable computer programs, for example the GAP program of the University of Wisconsin Genetic Computing Group and it will be appreciated that percent identity is calculated in relation to polypeptides whose sequence has been aligned optimally.

The alignment may alternatively be carried out using the Clustal W program (as described in Thompson et al., 1994, Nucl. Acid Res. 22:4673-4680, which is incorporated herein by reference). The parameters used may be as follows:

• • Fast pair-wise alignment parameters: K-tuple(word) size; 1, window size; 5, gap penalty; 3, number of top diagonals; 5. Scoring method: x percent.
  • Multiple alignment parameters: gap open penalty; 10, gap extension penalty; 0.05.
  • Scoring matrix: BLOSUM.

Alternatively, the BESTFIT program may be used to determine local sequence alignments.

In a further preferred embodiment, the antibody or antigen-binding fragment thereof according to the first aspect of the invention comprises a heavy chain variable region comprising the following CDRs:

• • a) G Y T V S S Y W I D [SEQ ID NO: 6] or an amino acid sequence having at least 60% sequence identity therewith, for example at least 70%, 80%, or 90% sequence identity;
  • b) E I L P G S A I N N Y N E K F K G [SEQ ID NO: 7] or an amino acid sequence having at least 60% sequence identity therewith, for example at least 70%, 80%, or 90% sequence identity; and
  • c) G D Y F D S T F V Y Y [SEQ ID NO: 5] or an amino acid sequence having at least 60% sequence identity therewith, for example at least 70%, 80%, or 90% sequence identity.

For example, the antibody polypeptide may comprise a heavy chain variable region comprising the CDRs of SEQ ID NOs 6, 7 and 5.

As indicated above, the CAN01 reference antibody is a murine antibody. However, the component heavy and light chains of this antibody may be humanised in order to produce antibody polypeptides more suitable for use in humans, e.g. due to their reduced immunogenicity. For example, the CDRs of SEQ ID NOs 3, 4 and 5 (or the CDRs of SEQ ID NOs 6, 7 and 5) may be engrafted into a human variable region framework.

It will be appreciated by persons skilled in the art that for human therapy or diagnostics, human or humanised antibodies are preferably used. Humanised forms of non-human (e.g. murine) antibodies are genetically engineered chimaeric antibodies or antibody fragments having preferably minimal-portions derived from non-human antibodies. Humanised antibodies include antibodies in which complementary determining regions of a human antibody (recipient antibody) are replaced by residues from a complementary determining region of a non-human species (donor antibody) such as mouse, rat of rabbit having the desired functionality. In some instances, Fv framework residues of the human antibody are replaced by corresponding non-human residues. Humanised antibodies may also comprise residues which are found neither in the recipient antibody nor in the imported complementarity determining region or framework sequences. In general, the humanised antibody will comprise substantially all of at least one, and typically two, variable domains, in which all or substantially all of the complementarity determining regions correspond to those of a non-human antibody and all, or substantially all, of the framework regions correspond to those of a relevant human consensus sequence. Humanised antibodies optimally also include at least a portion of an antibody constant region, such as an Fc region, typically derived from a human antibody (see, for example, Jones et al., 1986. Nature 321:522-525; Riechmann et al., 1988, Nature 332:323-329; Presta, 1992, Curr. Op. Struct. Biol. 2:593-596, the disclosures of which are incorporated herein by reference).

Methods for humanising non-human antibodies are well known in the art. Generally, the humanised antibody has one or more amino acid residues introduced into it from a source which is non-human. These non-human amino acid residues, often referred to as imported residues, are typically taken from an imported variable domain. Humanisation can be essentially performed as described (see, for example, Jones et al., 1986, Nature 321:522-525; Reichmann et al., 1988. Nature 332:323-327; Verhoeyen et al., 1988, Science 239:1534-15361; U.S. Pat. No. 4,816,567, the disclosures of which are incorporated herein by reference) by substituting human complementarity determining regions with corresponding rodent complementarity determining regions. Accordingly, such humanised antibodies are chimaeric antibodies, wherein substantially less than an intact human variable domain has been substituted by the corresponding sequence from a non-human species. In practice, humanised antibodies may be typically human antibodies in which some complementarity determining region residues and possibly some framework residues are substituted by residues from analogous sites in rodent antibodies.

Human antibodies can also be identified using various techniques known in the art, including phage display libraries (see, for example, Hoogenboom & Winter, 1991, J. Mol. Biol. 227:381; Marks et al., 1991, J. Mol. Biol. 222:581; Cole et al., 1985, In: Monoclonal antibodies and Cancer Therapy, Alan R. Liss, pp. 77; Boerner et al., 1991. J. Immunol. 147:86-95, the disclosures of which are incorporated herein by reference).

Thus, the antibody or antigen-binding fragment thereof of the invention may be humanised, for example it may comprise a heavy chain variable region having one of the following amino acid sequence of any one of SEQ ID NOs: 8 to 10 or an amino acid sequence having at least 90% sequence identity therewith:

[SEQ ID NO: 8]
a) E V Q L V Q S G A E V K K P G A T V K I S C K
   A S G Y T V S S Y W I D W V R Q A P G Q G L E
   W M G E I L P G S A I N N Y A E K F Q G R V T
   F T A D T S T D T A Y M E L S S L R S E D T A V
   Y Y C A S G D Y F D S T F V Y Y W G Q G T T V
   T V S S;
[SEQ ID NO: 9]
b) Q V Q L V Q S G A E V K K P G A T V K I S C K
   A S G Y T V S S Y W I D W V R Q A P G Q G L E
   W M G E I L P G S A I T N Y A E K F Q G R V T
   F T A D T S T S T A Y M E L S S L R S E D T A V
   Y Y C A S G D Y F D S T F V Y Y W G Q G T T V
   T V S S;
   or
[SEQ ID NO: 10]
c) Q V Q L V Q S G A E V K K P G A T V K I S C K
   A D G Y T V S S Y W I D W V R Q A P G Q G L E
   W M G E I L P G S A I T N Y A E K F Q G R V T
   F T A D T S T S T A Y M E L S S L R S E D T A T
   Y Y C A S G D Y F D S T F V Y Y W G Q G T T V
   T V S S.

For example, the antibody or antigen-binding fragment thereof may comprise a heavy chain variable region having an amino acid sequence of any one of SEQ ID NOs: 8 to 10.

In a related preferred embodiment, the antibody or antigen-binding fragment thereof comprises a light chain variable region comprising the following CDRs:

• • a) R S S Q S I V H S N G N T Y L E [SEQ ID NO:11] or an amino acid sequence having at least 60% sequence identity therewith, for example at least 70%, 80%, or 90% sequence identity;
  • b) K V S N R F S [SEQ ID NO: 12] or an amino acid sequence having at least 60% sequence identity therewith, for example at least 70%, 80%, or 90% sequence identity; and
  • c) F Q G S H V P R T [SEQ ID NO: 13] or an amino acid sequence having at least 60% sequence identity therewith, for example at least 70%, 80%, or 90% sequence identity.

Thus, the antibody or antigen-binding fragment thereof may comprise a light chain variable region comprising the CDRs of SEQ ID NOs 11, 12 and 13.

For example, the antibody or antigen-binding fragment thereof may comprise a light chain variable region having the amino acid sequence of the corresponding region of the murine CAN01 reference antibody, i.e. SEQ ID NO:2.

As in the case of the heavy chain variable region detailed above, it will be appreciated that the light chain variable region of the antibody polypeptide of the invention may be humanised in order to produce agents more suitable for use in humans. For example, the CDRs of SEQ ID NOs 11, 12 and 13 may be engrafted into a human variable region framework.

Thus, the antibody or antigen-binding fragment thereof may comprise a light chain variable region which comprises or consists of the amino acid sequence of any one of SEQ ID NOs: 14 to 18 or an amino acid sequence having at least 90% sequence identity therewith:

[SEQ ID NO: 14]
a) D I V M T Q S P L S L P V T P G E P A S I S C R
   S S Q S I V H S N G N T Y L E W Y L Q K P G Q
   S P Q L L I Y K V S N R F S G V P D R F S G S
   G S G T D F T L K I S R V E A E D V G V Y Y C F
   Q G S H V P R T F G G G T K V E I K R;
[SEQ ID NO: 15]
b) D I V M T Q S P L S L P V T P G Q P A S I S C R
   S S Q S I T H S N G N T Y L E W Y L Q K P G Q S
   P Q L L I Y K V S N R D S G V P D R F S G S G S
   G T D F T L K I S R V E A E D V G V Y Y C F Q
   G S H V P R T F G G G T K V E I K R;
[SEQ ID NO: 16]
c) D I V M T Q S P L S L P V T P G E P A S I S C R
   S S Q S I T H S N G Q T Y L E W Y L Q K P G Q
   S P Q L L I Y K V S N R A S G V P D R F S G S
   G S G T D F T L K I S R V E A E D V G V Y Y C F
   Q G S H V P R T F G G G T K V E I K R;
[SEQ ID NO: 17]
d) D I V M T Q S P L S L P V T P G E P A S I S C R
   S S Q S I T H S S G N T Y L E W Y L Q K P G Q S
   P Q L L I Y K V S N R A S G V P D R F S G S G
   S G T D F T L K I S R V E A E D V G V Y Y C F Q
   G S H V P R T F G G G T K V E I K R;
   or
[SEQ ID NO: 18]
e) D I V M T Q S P L S L P V T P G Q P A S I S C R
   S S Q S I T H S S G Q T Y L E W Y L Q K P G Q S
   P Q L L I Y K V S N R D S G V P D R F S G S G
   S G T D F T L K I S R V E A E D V G V Y Y C F Q
   G S H V P R T F G G G T K V E I K R.

For example, the antibody or antigen-binding fragment thereof may comprise a light chain variable region having an amino acid sequence of any one of SEQ ID NOs: 14 to 18.

In one embodiment, the antibody or antigen-binding fragment thereof comprises a murine heavy chain variable region which comprises or consists of the amino acid sequence of any one of SEQ ID NO: 1 and a murine light chain variable region which comprises or consists of the amino acid sequence of any one of SEQ ID NO: 2.

Alternatively, the antibody or antigen-binding fragment thereof may comprise a humanised heavy chain variable region which comprises or consists of the amino acid sequence of any one of SEQ ID NOs: 8 to 10 and a humanised light chain variable region which comprises or consists of the amino acid sequence of any one of SEQ ID NOs: 14 to 18.

For example, the antibody or antigen-binding fragment thereof may comprise:

• • a) a heavy chain variable region which comprises or consists of the amino acid sequence of SEQ ID NO: 8 and a light chain variable region which comprises or consists of the amino acid sequence of SEQ ID NO: 14;
  • b) a heavy chain variable region which comprises or consists of the amino acid sequence of SEQ ID NO: 9 and a light chain variable region which comprises or consists of the amino acid sequence of SEQ ID NO: 14;
  • c) a heavy chain variable region which comprises or consists of the amino acid sequence of SEQ ID NO: 10 and a light chain variable region which comprises or consists of the amino acid sequence of SEQ ID NO: 14;
  • b) a heavy chain variable region which comprises or consists of the amino acid sequence of SEQ ID NO: 8 and a light chain variable region which comprises or consists of the amino acid sequence of SEQ ID NO: 15;
  • d) a heavy chain variable region which comprises or consists of the amino acid sequence of SEQ ID NO: 9 and a light chain variable region which comprises or consists of the amino acid sequence of SEQ ID NO: 15;
  • e) a heavy chain variable region which comprises or consists of the amino acid sequence of SEQ ID NO: 10 and a light chain variable region which comprises or consists of the amino acid sequence of SEQ ID NO: 15;
  • c) a heavy chain variable region which comprises or consists of the amino acid sequence of SEQ ID NO: 8 and a light chain variable region which comprises or consists of the amino acid sequence of SEQ ID NO: 16;
  • f) a heavy chain variable region which comprises or consists of the amino acid sequence of SEQ ID NO: 9 and a light chain variable region which comprises or consists of the amino acid sequence of SEQ ID NO: 16;
  • g) a heavy chain variable region which comprises or consists of the amino acid sequence of SEQ ID NO: 10 and a light chain variable region which comprises or consists of the amino acid sequence of SEQ ID NO: 16;
  • d) a heavy chain variable region which comprises or consists of the amino acid sequence of SEQ ID NO: 8 and a light chain variable region which comprises or consists of the amino acid sequence of SEQ ID NO: 17;
  • h) a heavy chain variable region which comprises or consists of the amino acid sequence of SEQ ID NO: 9 and a light chain variable region which comprises or consists of the amino acid sequence of SEQ ID NO: 17;
  • i) a heavy chain variable region which comprises or consists of the amino acid sequence of SEQ ID NO: 10 and a light chain variable region which comprises or consists of the amino acid sequence of SEQ ID NO: 17;
  • e) a heavy chain variable region which comprises or consists of the amino acid sequence of SEQ ID NO: 8 and a light chain variable region which comprises or consists of the amino acid sequence of SEQ ID NO: 18;
  • j) a heavy chain variable region which comprises or consists of the amino acid sequence of SEQ ID NO: 9 and a light chain variable region which comprises or consists of the amino acid sequence of SEQ ID NO: 18; or
  • k) a heavy chain variable region which comprises or consists of the amino acid sequence of SEQ ID NO: 10 and a light chain variable region which comprises or consists of the amino acid sequence of SEQ ID NO: 18.

In an alternative embodiment, the antibody polypeptides of the invention are defined by reference to the variable regions of a murine-derived antibody, designated ‘CAN03’, which comprises:

(a) a heavy chain variable region having the amino
acid sequence of SEQ ID NO: 19:
[SEQ ID NO: 19]
D V K L V E S G G G L V K P G G S L K L S C A A
S G F T F S I Y T M S W V R Q T P E K R L E W V
A T I S I G G S Y I N Y P D S V K G R F T I S R D
N A K N T L Y L Q M S S L K S E D T A I Y Y C S R
E V D G S Y A M D Y W G Q G T S V T V S S
and
(b) a light chain variable region having the amino
acid sequence of SEQ ID NO: 20:
[SEQ ID NO: 20]
D I L L T Q S P A I L S V S P G E R V S F S C R A
S Q S I G T S I H W Y Q R R T N G S P R L L I K S
A S E S I S G I P S R F S G S G S G T D F T L S I
N S V E S E D I A D Y Y C Q Q S N S W P T T F G
A G T K L E L K R

It will be appreciated by persons skilled in the art that any intact IgG antibody comprising the above variable regions may be used as the reference antibody to identify antibody polypeptides of the invention that competitively inhibit CAN03 binding to IL1RAP (as described above in relation to the use of CAN01 as a reference antibody).

Thus, in one embodiment, the CAN03 antibody used as a reference to determine competitive binding is an intact IgG antibody comprising:

• • (a) a heavy chain comprising a variable domain of SEQ ID NO:19 grafted on to an murine IgG1 or IgG2a constant region; and
  • (b) a light chain comprising a variable domain of SEQ ID NO:20 grafted on to a murine kappa constant region.

Alternatively, the reference antibody may be a chimaeric, intact IgG antibody comprising:

• • (a) a heavy chain comprising a variable domain of SEQ ID NO:19 grafted on to an human IgG1 constant region (for example, such as SEQ ID NO:30; as encoded by the pFUSEss-CHIg-hG1 vector InvivoGen, San Diego, USA); and
  • (b) a light chain comprising a variable domain of SEQ ID NO:20 grafted on to a human kappa constant region (for example, such as SEQ ID NO:29; as encoded by the pFUSE2ss-CLIg-hk vector InvivoGen, San Diego, USA).

Suitable methods for determining whether a given test antibody is able to inhibit the binding of a reference antibody to an antigen are well known in the art (see above).

In one embodiment, the antibody or antigen-binding fragment which competitively inhibits CAN03-binding to IL1RAP exhibits one or more of the following properties:

• • (a) a binding affinity (K_D) for human IL1RAP of 500 pM or greater, i.e. the K_D≤500 pM (for example, as determined using the Biacore methodology in Example A);
  • (b) cross-reactivity with IL1RAP from Macaca fascicularis (for example, as determined in Example D);
  • (c) an inhibitory action on IL-1 signaling (for example, as determined in Example E);
  • (d) capability of inducing antibody-dependent cell-mediated cytotoxicity (ADCC) in one or more cancer cell lines (such as a CML, AML, ALL and/or melanoma cell lines, and/or cell line models of one or more of the other cancer types identified below) (for example, as determined in Examples F and G); and/or
  • (e) capability of internalisation upon binding to one or more cancer cell lines (such as a CML, AML, ALL and/or melanoma cell lines, and/or cell line models of one or more of the other cancer types identified below) (for example, as determined in Example H).

Advantageously, the antibody or antigen-binding fragment exhibits all of the above properties.

In one embodiment, the antibody or antigen-binding fragment further exhibits an inhibitory action on IL-33 signaling and/or IL-36 signaling (for example, as determined in Examples L and M below).

In one embodiment, the antibody or antigen-binding fragment is capable of binding to an epitope on the extracellular domain of IL1RAP which overlaps, at least in part, with the epitope on IL1RAP to which reference antibody CAN03 is capable of binding. Thus, the antibody or antigen-binding fragment may be capable of binding to an epitope located at/within domain 3 of IL1RAP, i.e. amino acids 235 to 367 (see above).

In a preferred embodiment, the antibody or antigen-binding fragment thereof according to the first aspect of the invention comprises a heavy chain variable region comprising the following CDRs:

• • a) G F T F S I Y [SEQ ID NO: 21] or an amino acid sequence having at least 60% sequence identity therewith, for example at least 70%, 80%, or 90% sequence identity;
  • b) S I G G S Y [SEQ ID NO: 22] or an amino acid sequence having at least 60% sequence identity therewith, for example at least 70%, 80%, or 90% sequence identity; and
  • c) E V D G S Y A M D Y [SEQ ID NO: 23] or an amino acid sequence having at least 60% sequence identity therewith, for example at least 70%, 80%, or 90% sequence identity.

Thus, the antibody or antigen-binding fragment thereof may comprise a heavy chain variable region comprising the CDRs of SEQ ID NOs 21, 22 and 23.

For example, the antibody or antigen-binding fragment thereof may comprise a heavy chain variable region having the amino acid sequence of the corresponding region of the CAN01 reference antibody, i.e. SEQ ID NO:19.

However, it will be appreciated that a low level of mutation (typically, just one or two amino acids) within a CDR sequence may be tolerated without loss of the specificity of the antibody or antigen-binding fragment for IL1RAP.

In a further preferred embodiment, the antibody or antigen-binding fragment thereof according to the first aspect of the invention comprises a heavy chain variable region comprising the following CDRs:

• • a) G F T F S I Y T M S [SEQ ID NO: 24] or an amino acid sequence having at least 60% sequence identity therewith, for example at least 70%, 80%, or 90% sequence identity;
  • b) T I S I G G S Y I N Y P D S V K G [SEQ ID NO:25] or an amino acid sequence having at least 60% sequence identity therewith, for example at least 70%, 80%, or 90% sequence identity; and
  • c) E V D G S Y A M D Y [SEQ ID NO: 23] or an amino acid sequence having at least 60% sequence identity therewith, for example at least 70%, 80%, or 90% sequence identity.

For example, the antibody polypeptide may comprise a heavy chain variable region comprising the CDRs of SEQ ID NOs 24, 25 and 23.

As indicated above, the CAN03 reference antibody is a murine antibody. However, the component heavy and light chains of this antibody may be humanised in order to produce antibody polypeptides more suitable for use in humans, e.g. due to their reduced immunogenicity. For example, the CDRs of SEQ ID NOs 21, 22 and 23 (or the CDRs of SEQ ID NOs 24, 25 and 23) may be engrafted into a human variable region framework.

In a related preferred embodiment, the antibody or antigen-binding fragment thereof comprises a light chain variable region comprising the following CDRs:

• • a) R A S Q S I G T S I H [SEQ ID NO: 26] or an amino acid sequence having at least 60% sequence identity therewith, for example at least 70%, 80%, or 90% sequence identity;
  • b) S A S E S I S [SEQ ID NO: 27] or an amino acid sequence having at least 60% sequence identity therewith, for example at least 70%, 80%, or 90% sequence identity; and
  • c) Q Q S N S W P T T [SEQ ID NO: 28] or an amino acid sequence having at least 60% sequence identity therewith, for example at least 70%, 80%, or 90% sequence identity

Thus, the antibody or antigen-binding fragment thereof may comprise a light chain variable region comprising the CDRs of SEQ ID NOs 26, 27 and 28.

For example, the antibody or antigen-binding fragment thereof may comprise a light chain variable region having the amino acid sequence of the corresponding region of the murine CAN01 reference antibody, i.e. SEQ ID NO:20.

As in the case of the heavy chain variable region detailed above, it will be appreciated that the light chain variable region of the antibody polypeptide of the invention may be humanised in order to produce agents more suitable for use in humans. For example, the CDRs of SEQ ID NOs 26, 27 and 28 may be engrafted into a human variable region framework.

In one embodiment, the antibody or antigen-binding fragment thereof comprises a murine heavy chain variable region which comprises or consists of the amino acid sequence of any one of SEQ ID NO: 19 and a murine light chain variable region which comprises or consists of the amino acid sequence of any one of SEQ ID NO: 20.

Alternatively, the antibody or antigen-binding fragment thereof may comprise a humanised heavy chain variable region which comprises or consists of the amino acid sequence of any one of SEQ ID NOs: 21 to 23 and a humanised light chain variable region which comprises or consists of the amino acid sequence of any one of SEQ ID NOs: 26 to 28.

It will be appreciated by persons skilled in the art that the above-defined antibodies or antigen-binding fragments of the invention may further comprise a heavy chain constant region, or part thereof.

In one embodiment, the antibody polypeptide comprises a CH1, CH2 and/or CH3 region of an IgG heavy chain (such as an IgG1, IgG2, IgG3 or IgG4 heavy chain). Thus, the antibody polypeptide may comprise part or all of the constant regions from an IgG1 heavy chain. For example, the antibody polypeptide may be a Fab fragment comprising CH1 and CL constant regions, combined with any of the above-defined heavy and light variable regions respectively.

Likewise, the above-defined antibodies or antigen-binding fragments of the invention may further comprise a light chain constant region, or part thereof. For example, the antibody polypeptide may comprise a CL region from a kappa or lambda light chain.

For example, the antibody polypeptide may comprise the following constant regions:

(a) Ig kappa chain C region (Homo sapiens)(Unit-
Prot Accession No. P01834)
[SEQ ID NO: 29]
TVAAPSVFIF PPSDEQLKSG TASVVCLLNN FYPREAKVQW
KVDNALQSGN SQESVTEQDS KDSTYSLSST LTLSKADYEK
HKVYACEVTH QGLSSPVTKS FNRGEC
(b) Ig gamma-1 chain C region (Homo sapiens)(Unit-
Prot Accession No. P01857)
[SEQ ID NO: 30]
ASTKGPSVFP LAPSSKSTSG GTAALGCLVK DYFPEPVTVS
WNSGALTSGV HTFPAVLQSS GLYSLSSVVT VPSSSLGTQT
YICNVNHKPS NTKVDKKVEP KSCDKTHTCP PCPAPELLGG
PSVFLFPPKP KDTLMISRTP EVTCVVVDVS HEDPEVKFNW
YVDGVEVHNA KTKPREEQYN STYRVVSVLT VLHQDWLNGK
EYKCKVSNKA LPAPIEKTIS KAKGQPREPQ VYTLPPSREE
MTKNQVSLTC LVKGFYPSDI AVEWESNGQP ENNYKTTPPV
LDSDGSFFLY SKLTVDKSRW QQGNVFSCSV MHEALHNHYT
QKSLSLSPGK

In an alternative embodiment, naturally occurring variants of the above constant regions may be utilised (e.g. see Jefferis & Lefranc, 2009, MAbs 1(4):332-8, the disclosures of which are incorporated herein by reference). For example, the light chain constant region may comprise or consist of SEQ ID NO: 29 having a W40R and/or V83L mutation and/or the heavy china constant region may comprise or consist of SEQ ID NO: 30 having a K97R, D239E and/or L241M mutation, or without the C-terminal lysine/K (wherein the position of the amino acid mutations is defined using the Eu Numbering Scheme, which differs from the numbering in SEQ ID NOS: 29 and 30; see Edelman et al., 1969, Proc. Natl. Acad. Sci. USA, 63:78-85, the disclosures of which are incorporated herein by reference).

Thus, exemplary antibody polypeptides of the invention include:

CAN01 and humanised versions thereof:

• • (a) a heavy chain comprising a variable region of SEQ ID NO: 1 (or a humanised version thereof, such as SEQ ID NO:8, 9 or 10) together with a constant region of SEQ ID NO: 30; and
  • (b) a light chain comprising a variable region of SEQ ID NO: 2 (or a humanised version thereof, such as SEQ ID NO:14, 15, 16, 17 or 18) together with a constant region of SEQ ID NO: 29.

CAN03 and humanised versions thereof:

• • (a) a heavy chain comprising a variable region of SEQ ID NO: 19 (or a humanised version thereof) together with a constant region of SEQ ID NO: 30; and
  • (b) a light chain comprising a variable region of SEQ ID NO: 20 (or a humanised version thereof) together with a constant region of SEQ ID NO: 29.

In a related embodiment, the antibody polypeptide may comprise an antibody Fc-region (e.g. the CH2 and CH3 regions of an IgG heavy chain). It will be appreciated by a skilled person that the Fc portion may be from an IgG antibody, or from a different class of antibody (such as IgM, IgA, IgD or IgE). In one embodiment, the Fc region is from an IgG1, IgG2, IgG3 or IgG4 antibody.

The Fc region may be naturally-occurring (e.g. part of an endogenously produced antibody) or may be artificial (e.g. comprising one or more point mutations relative to a naturally-occurring Fc region and/or modifications to the carbohydrate moieties within the CH2 domain).

As is well documented in the art, the Fc region of an antibody mediates its serum half-life and effector functions, such as complement-dependent cytotoxicity (CDC), antibody-dependent cellular cytotoxicity (ADCC) and antibody-dependent cell phagocytosis (ADCP).

Engineering the Fc region of a therapeutic monoclonal antibody or Fc fusion protein allows the generation of molecules that are better suited to the pharmacology activity required of them (Strohl, 2009, Curr Opin Biotechnol 20(6):685-91, the disclosures of which are incorporated herein by reference).

(a) Engineered Fc Regions for Increased Half-Life

One approach to improve the efficacy of a therapeutic antibody is to increase its serum persistence, thereby allowing higher circulating levels, less frequent administration and reduced doses.

The half-life of an IgG depends on its pH-dependent binding to the neonatal receptor FcRn. FcRn, which is expressed on the surface of endothelial cells, binds the IgG in a pH-dependent manner and protects it from degradation.

Some antibodies that selectively bind the FcRn at pH 6.0, but not pH 7.4, exhibit a higher half-life in a variety of animal models.

Several mutations located at the interface between the CH2 and CH3 domains, such as T250Q/M428L (Hinton et al., 2004, J Biol Chem. 279(8):6213-6, the disclosures of which are incorporated herein by reference) and M252Y/S254T/T256E +H433K/N434F (Vaccaro et al., 2005, Nat. Biotechnol. 23(10):1283-8, the disclosures of which are incorporated herein by reference), have been shown to increase the binding affinity to FcRn and the half-life of IgG1 in vivo.

(b) Engineered Fc Regions for Altered Effector Function

Depending on the therapeutic antibody or Fc fusion protein application, it may be desired to either reduce or increase the effector function (such as ADCC).

For antibodies that target cell-surface molecules, especially those on immune cells, abrogating effector functions may be required for certain clinical indications.

Conversely, for antibodies intended for oncology use (such as in the treatment of leukemias and solid tumours; see below), increasing effector functions may improve the therapeutic activity.

The four human IgG isotypes bind the activating Fcγ receptors (FcγRI, FcγRIIa, FcγRIIIa), the inhibitory FcγRIIb receptor, and the first component of complement (C1q) with different affinities, yielding very different effector functions (Bruhns et al., 2009, Blood. 113(16):3716-25, the disclosures of which are incorporated herein by reference).

Binding of IgG to the FcγRs or C1q depends on residues located in the hinge region and the CH2 domain. Two regions of the CH2 domain are critical for FcγRs and C1q binding, and have unique sequences in IgG2 and IgG4. Substitutions into human IgG1 of IgG2 residues at positions 233-236 and IgG4 residues at positions 327, 330 and 331 were shown to greatly reduce ADCC and CDC (Armour et al., 1999, Eur J Immunol. 29(8):2613-24; Shields et al., 2001, J Biol Chem. 276(9):6591-604, the disclosures of which are incorporated herein by reference). Furthermore, Idusogie et al. demonstrated that alanine substitution at different positions, including K322, significantly reduced complement activation (Idusogie et al., 2000, J Immunol. 164(8):4178-84, the disclosures of which are incorporated herein by reference). Similarly, mutations in the CH2 domain of murine IgG2A were shown to reduce the binding to FcγRI, and C1q (Steurer. et al., 1995. J Immunol. 155(3):1165-74, the disclosures of which are incorporated herein by reference).

Numerous mutations have been made in the CH2 domain of human IgG1 and their effect on ADCC and CDC tested in vitro (see references cited above). Notably, alanine substitution at position 333 was reported to increase both ADCC and CDC (Shields et al., 2001, supra; Steurer et al., 1995, supra). Lazar et al. described a triple mutant (S239D/I332E/A330L) with a higher affinity for FcγRIIIa and a lower affinity for FcγRIIb resulting in enhanced ADCC (Lazar et al., 2006, PNAS 103(11):4005-4010, the disclosures of which are incorporated herein by reference). The same mutations were used to generate an antibody with increased ADCC (Ryan et al., 2007, Mol. Cancer Ther. 6:3009-3018, the disclosures of which are incorporated herein by reference). Richards et al. studied a slightly different triple mutant (S239D/I332E/G236A) with improved FcγRIIIa affinity and FcγRIIa/FcγRIIb ratio that mediates enhanced phagocytosis of target cells by macrophages (Richards et al., 2008. Mol Cancer Ther. 7(8):2517-27, the disclosures of which are incorporated herein by reference).

Due to their lack of effector functions, IgG4 antibodies represent a preferred IgG subclass for receptor blocking without cell depletion (i.e. inhibition of IL-1 signaling). IgG4 molecules can exchange half-molecules in a dynamic process termed Fab-arm exchange. This phenomenon can also occur in vivo between therapeutic antibodies and endogenous IgG4.

The S228P mutation has been shown to prevent this recombination process allowing the design of less unpredictable therapeutic IgG4 antibodies (Labrijn et al., 2009, Nat Biotechnol. 27(8):767-71, the disclosures of which are incorporated herein by reference).

Examples of engineered Fc regions are shown in Table 1 below.

TABLE 1
Examples of Engineered Fc
				Effector
Isotype	Species	Mutations*	FcR/C1q Binding	Function
IgG1	Human	T250Q/M428L1	Increased binding	Increased half-
			to FcRn	life
IgG1	Human	M252Y/S254T/T256E +	Increased binding	Increased half-
		H433K/N434F2	to FcRn	life
IgG1	Human	M428L/N434S3	Increased binding	Increased half-
			to FcRn	life
IgG1	Human	E233P/L234V/L235A/?G236 +	Reduced binding	Reduced
		A327G/A330S/P331S4,5	to FcγRI	ADCC and
				CDC
IgG1	Human	S239D/S298A/I332E +	Increased binding	Increased
		S239D/A330L/I332E6	to FcγRIIIa	ADCC
IgG1	Human	S239D/I332E7	Increased binding	Increased
			to FcγRIIIa	ADCC
IgG1	Human	S298A/E333A/K334A8	Increased binding	Increased
			to FcγRIIIa	ADCC
IgG1	Human	E333A9	Increased binding	Increased
			to FcγRIIIa	ADCC and
				CDC
IgG1	Human	P257I/Q31110	Increased binding	Unchanged
			to FcRn	half-life
IgG1	Human	K326W/E333S11	Increased binding	Increased CDC
			to C1q
IgG1	Human	S239D/I332E/G236A12	Increased	Increased
			FcγRIIa/FcγRIIb	macrophage
			ratio	phagocytosis
IgG1	Human	K322A8	Reduced binding	Reduced CDC
			to C1q
		N297S		Reduced
				(abrogated)
				ADCC
		N297Q		Reduced
				(abrogated)
				ADCC
		R292P + V305I +/− F243L13		Increased
				ADCC
		P247I/A339Q14		Increased
				ADCC
IgG4	Human	S228P15	—	Reduced Fab-
				arm exchange
IgG2a	Mouse	L235E + E318A/K320A/K322A11	Reduced binding	Reduced
			to FcγRI and C1q	ADCC and
				CDC
*The position of the Fc amino acid mutations is defined using the Eu Numbering Scheme, which differs from the numbering in SEQ ID NOS: 18 and 19 above; see Edelman et al., 1969, Proc. Natl. Acad. Sci. USA, 63: 78-85)
References to Table 1
1Hinton et al 2004 J. Biol. Chem. 279(8): 6213-6)
2Vaccaro et al. 2005 Nat Biotechnol. 23(10): 1283-8)
3Zalevsky et al 2010 Nat. Biotechnology 28(2): 157-159
4Armour K L. et al., 1999. Eur J Immunol. 29(8): 2613-24
5Shields R L. et al., 2001. J Biol Chem. 276(9): 6591-604
6Masuda et al. 2007, Mol Immunol. 44(12): 3122-31
7Bushfield et al 2014, Leukemia 28(11): 2213-21
8Okazaki et al. 2004, J Mol Biol.; 336(5): 1239-49
9Idusogie et al., 2000. J Immunol. 164(8): 4178-84
10Datta-Mannan A. et al., 2007. Drug Metab. Dispos. 35: 86-94
11Steurer W. et al., 1995. J Immunol. 155(3): 1165-74
12Richards et al. 2008 Mol Cancer There. 7(8): 2517-27
13U.S. Pat. No. 7,960,512 B2
14EP 2 213 683
15Labrijn A F. et al., 2009. Nat Biotechnol. 27(8): 767-71

In a further embodiment, the effector function of the Fc region may be altered through modification of the carbohydrate moieties within the CH2 domain therein.

For example, it is known that therapeutic antibodies lacking or low in fucose residues in the Fc region may exhibit enhanced ADCC activity in humans (for example, see Peipp et al., 2008, Blood 112(6):2390-9, Yamane-Ohnuki & Satoh, 2009, MAbs 1(3):230-26, lida et al., 2009, BMC Cancer 9; 58 (the disclosures of which are incorporated herein by reference). Low fucose antibody polypeptides may be produced by expression in cells cultured in a medium containing an inhibitor of mannosidase, such as kinfunensine (see Example I below).

Other methods to modify glycosylation of an antibody into a low fucose format include the use of the bacterial enzyme GDP-6-deoxy-D-lyxo-4-hexulose reductase in cells not able to metabolise rhamnose (e.g. using the GlymaxX® technology of ProBioGen AG, Berlin, Germany).

Another method to create low fucose antibodies is by inhibition or depletion of alpha-(1,6)-fucosyltransferase in the antibody-producing cells (e.g. using the Potelligent® CHOK1SV technology of Lonza Ltd, Basel, Switzerland).

As noted above, the antibody polypeptides of the invention may exert an inhibitory action on IL-1 signaling (see Examples E, L and M), either in addition to or in the absence of any Fc-mediated effector functions.

In one embodiment, the antibody polypeptides of the invention may exert an inhibitory action on one or more additional (or alternative) cytokines within the IL-1 superfamily, including but not limited to IL-33 and/or IL-36.

Interleukin-33 (IL-33) induces helper T cells, mast cells, eosinophils and basophils to produce type 2 cytokines. This cytokine was previously named NF-HEV ‘nuclear factor (NF) in high endothelial venules’ (HEVs) since it was originally identified in these specialized cells. IL-33 mediates its biological effects by interacting with the receptors ST2 (also known as IL1RL1) and IL-1 Receptor Accessory Protein (IL1RAP), activating intracellular molecules in the NF-κB and MAP kinase signaling pathways that drive production of type 2 cytokines (e.g. IL-5 and IL-13) from polarised Th2 cells. The induction of type 2 cytokines by IL-33 in vivo is believed to induce the severe pathological changes observed in mucosal organs following administration of IL-33.

Interleukin-36 (IL-36) is a cytokine that predominantly acts on naive CD4+ T cells via the IL-36 receptor. It is known to activate NF-κB and mitogen-activated protein kinases to play a role in skin pathology. It has also been found to activate T cell proliferation and release of IL-2.

It will be appreciated by persons skilled in the art that the antibody polypeptide of the invention may inhibit IL-1, IL-33 and/or IL-36 signaling in whole or in part. For example, signaling may be inhibited by at least 10%, 20%, 30%, 50%, 75% or more relative to signalling in the absence of the polypeptide of the invention.

The degree of inhibition of IL-1, IL-33 and/or IL-36 signalling by the polypeptide of the invention may be determined using methods well known in the art.

For example, inhibition of IL-1 signalling may be measured as described in Examples E, L and M below.

Likewise, inhibition of IL-33 signaling may be measured as described in Example E, L and M.

Inhibition of IL-36 signaling may be measured by methods known in the art. For example, IL-36 stimulation of synovial fibroblasts leads to NF-κB and MAP kinase activation. Alternatively, IL-36-α, -β and -γ increase T-cell proliferation in response to antiCD3/anti-CD28 stimulation (see Vigne et al., 2012, Blood 120(17):3478-87, the disclosures of which are incorporated herein by reference).

In one embodiment, the antibody or antigen-binding fragment thereof may further comprise a moiety for increasing the in vivo half-life of the antibody or antigen-binding fragment, such as but not limited to polyethylene glycol (PEG), human serum albumin, glycosylation groups, fatty acids and dextran. Such further moieties may be conjugated or otherwise combined with the binding moiety using methods well known in the art.

It will be appreciated by persons skilled in the art that the antibody polypeptides of the invention may comprise or consist of one or more amino acids which have been modified or derivatised.

Chemical derivatives of one or more amino acids may be achieved by reaction with a functional side group. Such derivatised molecules include, for example, those molecules in which free amino groups have been derivatised to form amine hydrochlorides, p-toluene sulphonyl groups, carboxybenzoxy groups, t-butyloxycarbonyl groups, chloroacetyl groups or formyl groups. Free carboxyl groups may be derivatised to form salts, methyl and ethyl esters or other types of esters and hydrazides. Free hydroxyl groups may be derivatised to form O-acyl or O-alkyl derivatives. Also included as chemical derivatives are those peptides which contain naturally occurring amino acid derivatives of the twenty standard amino acids. For example: 4-hydroxyproline may be substituted for proline; 5-hydroxylysine may be substituted for lysine; 3-methylhistidine may be substituted for histidine; homoserine may be substituted for serine and ornithine for lysine. Derivatives also include peptides containing one or more additions or deletions as long as the requisite activity is maintained. Other included modifications are amidation, amino terminal acylation (e.g. acetylation or thioglycolic acid amidation), terminal carboxylamidation (e.g. with ammonia or methylamine), and the like terminal modifications.

It will be further appreciated by persons skilled in the art that peptidomimetic compounds may also be useful. The term ‘peptidomimetic’ refers to a compound that mimics the conformation and desirable features of a particular peptide as a therapeutic agent.

For example, the said polypeptide includes not only molecules in which amino acid residues are joined by peptide (—CO—NH—) linkages but also molecules in which the peptide bond is reversed. Such retro-inverso peptidomimetics may be made using methods known in the art, for example such as those described in Meziere et al. (1997) J. Immunol. 159, 3230-3237, which is incorporated herein by reference. This approach involves making pseudo-peptides containing changes involving the backbone, and not the orientation of side chains. Retro-inverse peptides, which contain NH—CO bonds instead of CO—NH peptide bonds, are much more resistant to proteolysis. Alternatively, the said polypeptide may be a peptidomimetic compound wherein one or more of the amino acid residues are linked by a -y(CH₂NH)— bond in place of the conventional amide linkage.

In a further alternative, the peptide bond may be dispensed with altogether provided that an appropriate linker moiety which retains the spacing between the carbon atoms of the amino acid residues is used; it may be advantageous for the linker moiety to have substantially the same charge distribution and substantially the same planarity as a peptide bond.

It will also be appreciated that the said polypeptide may conveniently be blocked at its N- or C-terminus so as to help reduce susceptibility to exo-proteolytic digestion.

A variety of un-coded or modified amino acids such as D-amino acids and N-methyl amino acids have also been used to modify mammalian peptides. In addition, a presumed bioactive conformation may be stabilised by a covalent modification, such as cyclisation or by incorporation of lactam or other types of bridges, for example see Veber et al., 1978, Proc. Natl. Acad. Sci. USA 75:2636 and Thursell et al., 1983, Biochem. Biophys. Res. Comm. 111:166, which are incorporated herein by reference.

The antibody polypeptides of the invention may be augmented with a functional moiety to facilitate their intended use, for example as a diagnostic (e.g. in vivo imaging) agent or therapeutic agent. Thus, in one embodiment, the antibody polypeptide is linked, directly or indirectly, to a therapeutic moiety.

In one embodiment, the antibody or antigen-binding fragment thereof according to any one of the preceding claim further comprising a therapeutic (e.g. cytotoxic) moiety.

Any suitable therapeutic moiety may be used. A suitable therapeutic moiety is one that is capable of reducing or inhibiting the growth, or in particular killing, a cancer cell (or associated stem cells or progenitor cells). For example, the therapeutic agent may be a cytotoxic moiety. The cytotoxic moiety may comprise or consist of one or more radioisotopes. For example, the one or more radioisotopes may each be independently selected from the group consisting of beta-emitters, Auger-emitters, conversion electron-emitters, alpha-emitters, and low photon energy-emitters. It may be desired that the one or more radioisotopes each independently has an emission pattern of locally absorbed energy that creates a high absorbed dose in the vicinity of the agent. Exemplary radioisotopes may include long-range beta-emitters, such as ⁹⁰Y, ³²P, ¹⁸⁶Re/¹⁸⁸Re; ¹⁶⁶Ho, ⁷⁶AS/⁷⁷AS, ⁸⁹Sr, ¹⁵³Sm; medium range beta-emitters, such as ¹³¹I, ¹⁷⁷Lu, ⁶⁷Cu, 161Tb, ¹⁰⁵Rh; low-energy beta-emitters, such as ⁴⁵Ca or ³⁵S; conversion or Auger-emitters, such as ⁵¹Cr, ⁶⁷Ga, ⁹⁹Tc^m, ¹¹¹In, ¹²³I, ¹²⁵I, ²⁰¹TI; and alpha-emitters, such as ²¹²Bi, ²¹³Bi, ²²³Ac, ²²⁵Ac, ²¹²Pb, ²⁵⁵Fm, ²²³Ra, ¹⁴⁹Tb and ²²¹At. Other radionuclides are available and will be possible to use for therapy.

In one preferred embodiment, the antibody polypeptide is linked to (or otherwise labelled with) the radioisotope ¹⁷⁷Lu.

Alternatively, the therapeutic moiety may comprise or consist of one or more therapeutic (such as cytotoxic) drugs, for example, a cytostatic drug; an anti-androgen drug; cortisone and derivatives thereof; a phosphonate; a testosterone-5-α-reductase inhibitor; a boron addend; a cytokine; thapsigargin and its metabolites; a toxin (such as saporin or calicheamicin); a chemotherapeutic agent (such as an antimetabolite); or any other therapeutic or cytotoxic drug useful in the treatment of cancers.

Exemplary therapeutic/cytotoxic drugs may, for example, include:

• • Cytostatics, in particular those with dose-limiting side-effects, including but not limited to cyclophosamide, chlorambucil, ifosfamide, busulphane, lomustine, taxanes, estramustine phosphate and other nitrogen mustards, antibiotics (including doxorubicine, calicheamicines and esperamicine), vinca alkaloids, azaridines, platinum-containing compounds, endostatin, alkyl sulfonates, nitrosoureas, triazenes, folic acid analoges, pyrimidine analoges, purine analogs, enzymes, substituted urea, methyl-hydrazine derivatives, daunorubicin, amphipathic amines,
  • Anti-androgens such as flutamide and bikalutamide and metabolites thereof;
  • Cortisone and derivatives thereof;
  • Phosphonates such as diphophonate and buphosphonate;
  • Testosterone-5-α-reductase inhibitors;
  • Boron addends;
  • Cytokines;
  • Thapsigargin and its metabolites.
  • Bacterial toxins or engineered variants of these.
  • Immune modulators

Alternatively, the cytotoxic moiety may comprise or consist of one or more moieties suitable for use in activation therapy, such as photon activation therapy, neutron activation therapy, neutron-induced Auger electron therapy, synchrotron irradiation therapy or low energy X-ray photon activation therapy.

For example, with the antibody polypeptides of the invention there will be the potential of using synchrotron radiation (or low energy X-rays) for the advancement of radiotherapy, primarily focusing on so called photo-activation radiotherapy (PAT), in which the local energy deposition from external X-ray irradiation is enhanced in the cancer tissue by the interaction with a pre-administered, high-Z tumour-targeting agent.

The PAT treatment modality utilises monochromatic X-rays from a synchrotron source, such as provided by the ID17 biomedical beamline at the European Synchrotron Radiation Facility (ESRF) in Grenoble, and as anticipated to be available at other facilities in the future such as the new Swedish synchrotron facility, Max-IV.

Research on “induced Auger electron tumour therapy”, to be conducted at the coming European Spallation Source (ESS) in Lund, provides a further potential treatment modality. Reactor-produced thermal and semi-thermal neutrons have for long been used for Boron-Neutron-Capture-Therapy, BNCT, both for pre-clinical experiments and for treatment of brain tumours with the induced alpha-particles and the recoil nucleus (⁷L) that give a high locally absorbed energy. A similar approach is to use neutrons and suitable tumour-targeting molecules labelled with stable nuclei with high cross-section for neutrons. Antibodies or peptides can for instance be labelled with stable Gadolinium (¹⁵⁷Gd) and act as the target molecule for the neutrons that are captured by the Gd-nucleus, so called Gadolinium Neutron Capture Therapy (GdNCT). By Monte Carlo techniques, the dose distribution in the tumour and the surrounding tissues is calculated as it results from γ-photons, neutrons, nuclear recoils, as well as characteristic x-rays, internal conversion and Auger-electrons from gadolinium or other potential elements.

Optionally, the antibody polypeptide of the invention may further comprise a detectable moiety. For example, a detectable moiety may comprise or consist of a radioisotope, such as a radioisotope selected from the group consisting of ^99mTc, ¹¹¹In, ⁶⁷Ga, ⁶⁸Ga, ⁷²As, ⁸⁹Zr, ¹²³I and ²⁰¹TI. Optionally, the agent may comprise a pair of detectable and cytotoxic radionuclides, such as ⁸⁶Y/⁹⁰Y or ¹²⁴I/²¹¹At. Alternatively, the antibody polypeptide may comprise a radioisotope that is capable of simultaneously acting in a multi-modal manner as a detectable moiety and also as a cytotoxic moiety to provide so-called “Multimodality theragnostics”. The binding moieties may thus be coupled to nanoparticles that have the capability of multi-imaging (for example, SPECT, PET, MRI, Optical, or Ultrasound) together with therapeutic capability using cytotoxic drugs, such as radionuclides or chemotherapy agents.

Alternatively, the detectable moiety may comprise or consist of a paramagnetic isotope, such as a paramagnetic isotope is selected from the group consisting of ¹⁵⁷Gd, ⁵⁵Mn, ¹⁶²Dy, ⁵²Cr and ⁵⁶Fe.

In the case that the antibody polypeptide comprises a detectable moiety, then the detectable moiety may be detectable by an imaging technique such as SPECT, PET, MRI, optical or ultrasound imaging.

Therapeutic and/or detectable moieties (such as a radioisotope, cytotoxic moiety or the like) may be linked directly, or indirectly, to the antibody or fragment thereof. Suitable linkers are known in the art and include, for example, prosthetic groups, non-phenolic linkers (derivatives of N-succimidyl-benzoates; dodecaborate), chelating moieties of both macrocyclics and acyclic chelators, such as derivatives of 1,4,7,10-tetraazacyclododecane-1,4,7,10,tetraacetic acid (DOTA), deferoxamine (DFO), derivatives of diethylenetriaminepentaacetic avid (DTPA), derivatives of S-2-(4-lsothiocyanatobenzyl)-1,4,7-triazacyclononane-1,4,7-triacetic acid (NOTA) and derivatives of 1,4,8,11-tetraazacyclodocedan-1,4,8,11-tetraacetic acid (TETA), derivatives of 3,6,9,15-Tetraazabicyclo[9.3.1]-pentadeca-1(15)11,13-triene-4-(S)-(4-isothiocyanato-benzyl)-3,6,9-triacetic acid (PCTA), derivatives of 5-S-(4-AminobenzyI)-1-oxa-4,7,10-triazacyclododecane-4,7,10-tris(acetic acid) (DO3A) and other chelating moieties.

One preferred linker is DTPA, for example as used in ¹⁷⁷Lu-DTPA-[antibody polypeptide of the invention]. A further preferred linker is deferoxamine, DFO, for example as used in ⁸⁹Zr-DFO-[antibody polypeptide of the invention].

As discussed above, methods for the production of antibody polypeptides of the invention are well known in the art.

Conveniently, the antibody polypeptide is or comprises a recombinant polypeptide. Suitable methods for the production of such recombinant polypeptides are well known in the art, such as expression in prokaryotic or eukaryotic hosts cells (for example, see Green & Sambrook, 2012, Molecular Cloning, A Laboratory Manual, Fourth Edition, Cold Spring Harbor, N.Y., the relevant disclosures in which document are hereby incorporated by reference).

Antibody polypeptides of the invention can also be produced using a commercially available in vitro translation system, such as rabbit reticulocyte lysate or wheatgerm lysate (available from Promega). Preferably, the translation system is rabbit reticulocyte lysate. Conveniently, the translation system may be coupled to a transcription system, such as the TNT transcription-translation system (Promega). This system has the advantage of producing suitable mRNA transcript from an encoding DNA polynucleotide in the same reaction as the translation.

It will be appreciated by persons skilled in the art that antibody polypeptides of the invention may alternatively be synthesised artificially, for example using well known liquid-phase or solid phase synthesis techniques (such as t-Boc or Fmoc solid-phase peptide synthesis).

A second aspect of the invention provides an isolated nucleic acid molecule encoding an antibody or antigen-binding fragment of the first aspect of the invention, or a component polypeptide chain thereof. By “nucleic acid molecule” we include DNA (e.g. genomic DNA or complementary DNA) and mRNA molecules, which may be single- or double-stranded. By “isolated” we mean that the nucleic acid molecule is not located or otherwise provided within a cell.

In one embodiment, the nucleic acid molecule is a cDNA molecule.

It will be appreciated by persons skilled in the art that the nucleic acid molecule may be codon-optimised for expression of the antibody polypeptide in a particular host cell, e.g. for expression in human cells (for example, see Angov, 2011, Biotechnol. J. 6(6):650-659, the disclosures of which are incorporated herein by reference).

Also included within the scope of the invention are the following:

• • (a) a third aspect of the invention provides a vector (such as an expression vector) comprising a nucleic acid molecule according to the second aspect of the invention;
  • (b) a fourth aspect of the invention provides a host cell (such as a mammalian cell, e.g. human cell, or Chinese hamster ovary cell, e.g. CHOK1SV cells) comprising a nucleic acid molecule according to the second aspect of the invention or a vector according to the third aspect of the invention; and
  • (c) a fifth aspect of the invention provides a method of making an antibody polypeptide according to the first aspect of the invention comprising culturing a population of host cells according to the fourth aspect of the invention under conditions in which said polypeptide is expressed, and isolating the polypeptide therefrom.

A sixth aspect of the invention provides a pharmaceutical composition comprising a pharmaceutically effective amount of an antibody or antigen-binding fragment according to the first aspect of the invention and a pharmaceutically-acceptable diluent, carrier, adjuvant or excipient.

It will be appreciated by persons skilled in the art that additional compounds may also be included in the pharmaceutical compositions, including, chelating agents such as EDTA, citrate, EGTA or glutathione.

The pharmaceutical compositions may be prepared in a manner known in the art that is sufficiently storage stable and suitable for administration to humans and animals. For example, the pharmaceutical compositions may be lyophilised, e.g. through freeze drying, spray drying, spray cooling, or through use of particle formation from supercritical particle formation.

By “pharmaceutically acceptable” we mean a non-toxic material that does not decrease the effectiveness of the IL1RAP-binding activity of the antibody polypeptide of the invention. Such pharmaceutically acceptable buffers, carriers or excipients are well-known in the art (see Remington's Pharmaceutical Sciences, 18th edition, A. R Gennaro, Ed., Mack Publishing Company (1990) and handbook of Pharmaceutical Excipients, 3rd edition, A. Kibbe, Ed., Pharmaceutical Press (2000), the disclosures of which are incorporated herein by reference).

The term “buffer” is intended to mean an aqueous solution containing an acid-base mixture with the purpose of stabilising pH. Examples of buffers are Trizma, Bicine, Tricine, MOPS, MOPSO, MOBS, Tris, Hepes, HEPBS, MES, phosphate, carbonate, acetate, citrate, glycolate, lactate, borate, ACES, ADA, tartrate, AMP, AMPD, AMPSO, BES, CABS, cacodylate, CHES, DIPSO, EPPS, ethanolamine, glycine, HEPPSO, imidazole, imidazolelactic acid, PIPES, SSC, SSPE, POPSO, TAPS, TABS, TAPSO and TES.

The term “diluent” is intended to mean an aqueous or non-aqueous solution with the purpose of diluting the antibody polypeptide in the pharmaceutical preparation. The diluent may be one or more of saline, water, polyethylene glycol, propylene glycol, ethanol or oils (such as safflower oil, corn oil, peanut oil, cottonseed oil or sesame oil).

The term “adjuvant” is intended to mean any compound added to the formulation to increase the biological effect of the antibody polypeptide of the invention. The adjuvant may be one or more of zinc, copper or silver salts with different anions, for example, but not limited to fluoride, chloride, bromide, iodide, tiocyanate, sulfite, hydroxide, phosphate, carbonate, lactate, glycolate, citrate, borate, tartrate, and acetates of different acyl composition. The adjuvant may also be cationic polymers such as cationic cellulose ethers, cationic cellulose esters, deacetylated hyaluronic acid, chitosan, cationic dendrimers, cationic synthetic polymers such as poly(vinyl imidazole), and cationic polypeptides such as polyhistidine, polylysine, polyarginine, and peptides containing these amino acids.

The excipient may be one or more of carbohydrates, polymers, lipids and minerals. Examples of carbohydrates include lactose, glucose, sucrose, mannitol, and cyclodextrines, which are added to the composition, e.g. for facilitating lyophilisation. Examples of polymers are starch, cellulose ethers, cellulose carboxymethylcellulose, hydroxypropylmethyl cellulose, hydroxyethyl cellulose, ethylhydroxyethyl cellulose, alginates, carageenans, hyaluronic acid and derivatives thereof, polyacrylic acid, polysulphonate, polyethylenglycol/polyethylene oxide, polyethyleneoxide/polypropylene oxide copolymers, polyvinylalcohol/polyvinylacetate of different degree of hydrolysis, and polyvinylpyrrolidone, all of different molecular weight, which are added to the composition, e.g., for viscosity control, for achieving bioadhesion, or for protecting the lipid from chemical and proteolytic degradation. Examples of lipids are fatty acids, phospholipids, mono-, di-, and triglycerides, ceramides, sphingolipids and glycolipids, all of different acyl chain length and saturation, egg lecithin, soy lecithin, hydrogenated egg and soy lecithin, which are added to the composition for reasons similar to those for polymers. Examples of minerals are talc, magnesium oxide, zinc oxide and titanium oxide, which are added to the composition to obtain benefits such as reduction of liquid accumulation or advantageous pigment properties.

The antibody polypeptides of the invention may be formulated into any type of pharmaceutical composition known in the art to be suitable for the delivery thereof.

In one embodiment, the pharmaceutical compositions of the invention may be in the form of a liposome, in which the antibody polypeptide is combined, in addition to other pharmaceutically acceptable carriers, with amphipathic agents such as lipids, which exist in aggregated forms as micelles, insoluble monolayers and liquid crystals. Suitable lipids for liposomal formulation include, without limitation, monoglycerides, diglycerides, sulfatides, lysolecithin, phospholipids, saponin, bile acids, and the like. Suitable lipids also include the lipids above modified by poly(ethylene glycol) in the polar headgroup for prolonging bloodstream circulation time. Preparation of such liposomal formulations is can be found in for example U.S. Pat. No. 4,235,871, the disclosures of which are incorporated herein by reference.

The pharmaceutical compositions of the invention may also be in the form of biodegradable microspheres. Aliphatic polyesters, such as poly(lactic acid) (PLA), poly(glycolic acid) (PGA), copolymers of PLA and PGA (PLGA) or poly(caprolactone) (PCL), and polyanhydrides have been widely used as biodegradable polymers in the production of microspheres. Preparations of such microspheres can be found in U.S. Pat. No. 5,851,451 and in EP 0 213 303, the disclosures of which are incorporated herein by reference.

In a further embodiment, the pharmaceutical compositions of the invention are provided in the form of polymer gels, where polymers such as starch, cellulose ethers, cellulose carboxymethylcellulose, hydroxypropylmethyl cellulose, hydroxyethyl cellulose, ethylhydroxyethyl cellulose, alginates, carageenans, hyaluronic acid and derivatives thereof, polyacrylic acid, polyvinyl imidazole, polysulphonate, polyethylenglycol/polyethylene oxide, polyethyleneoxide/polypropylene oxide copolymers, polyvinylalcohol/polyvinylacetate of different degree of hydrolysis, and polyvinylpyrrolidone are used for thickening of the solution containing the agent. The polymers may also comprise gelatin or collagen.

Alternatively, the antibody polypeptide may simply be dissolved in saline, water, polyethylene glycol, propylene glycol, ethanol or oils (such as safflower oil, corn oil, peanut oil, cottonseed oil or sesame oil), tragacanth gum, and/or various buffers.

It will be appreciated that the pharmaceutical compositions of the invention may include ions and a defined pH for potentiation of action of the active antibody polypeptide. Additionally, the compositions may be subjected to conventional pharmaceutical operations such as sterilisation and/or may contain conventional adjuvants such as preservatives, stabilisers, wetting agents, emulsifiers, buffers, fillers, etc.

The pharmaceutical compositions according to the invention may be administered via any suitable route known to those skilled in the art. Thus, possible routes of administration include parenteral (intravenous, subcutaneous, and intramuscular), topical, ocular, nasal, pulmonar, buccal, oral, parenteral, vaginal and rectal. Also administration from implants is possible.

In one preferred embodiment, the pharmaceutical compositions are administered parenterally, for example, intravenously, intracerebroventricularly, intraarticularly, intra-arterially, intraperitoneally, intrathecally, intraventricularly, intrasternally, intracranially, intramuscularly or subcutaneously, or they may be administered by infusion techniques.

They are conveniently used in the form of a sterile aqueous solution which may contain other substances, for example, enough salts or glucose to make the solution isotonic with blood. The aqueous solutions should be suitably buffered (preferably to a pH of from 3 to 9), if necessary. The preparation of suitable parenteral formulations under sterile conditions is readily accomplished by standard pharmaceutical techniques well known to those skilled in the art.

Formulations suitable for parenteral administration include aqueous and non-aqueous sterile injection solutions which may contain anti-oxidants, buffers, bacteriostats and solutes which render the formulation isotonic with the blood of the intended recipient; and aqueous and non-aqueous sterile suspensions which may include suspending agents and thickening agents. The formulations may be presented in unit-dose or multi-dose containers, for example sealed ampoules and vials, and may be stored in a freeze-dried (lyophilised) condition requiring only the addition of the sterile liquid carrier, for example water for injections, immediately prior to use. Extemporaneous injection solutions and suspensions may be prepared from sterile powders, granules and tablets of the kind previously described.

Thus, the pharmaceutical compositions of the invention are particularly suitable for parenteral, e.g. intravenous, administration.

Alternatively, the pharmaceutical compositions may be administered intranasally or by inhalation (for example, in the form of an aerosol spray presentation from a pressurised container, pump, spray or nebuliser with the use of a suitable propellant, such as dichlorodifluoromethane, trichlorofluoro-methane, dichlorotetrafluoro-ethane, a hydrofluoroalkane such as 1,1,1,2-tetrafluoroethane (HFA 134A3 or 1,1,1,2,3,3,3-heptafluoropropane (HFA 227EA3), carbon dioxide or other suitable gas). In the case of a pressurised aerosol, the dosage unit may be determined by providing a valve to deliver a metered amount. The pressurised container, pump, spray or nebuliser may contain a solution or suspension of the active polypeptide, e.g. using a mixture of ethanol and the propellant as the solvent, which may additionally contain a lubricant, e.g. sorbitan trioleate. Capsules and cartridges (made, for example, from gelatin) for use in an inhaler or insufflator may be formulated to contain a powder mix of a compound of the invention and a suitable powder base such as lactose or starch.

The pharmaceutical compositions will be administered to a patient in a pharmaceutically effective dose. A ‘therapeutically effective amount’, or ‘effective amount’, or ‘therapeutically effective’, as used herein, refers to that amount which provides a therapeutic effect for a given condition and administration regimen. This is a predetermined quantity of active material calculated to produce a desired therapeutic effect in association with the required additive and diluent, i.e. a carrier or administration vehicle. Further, it is intended to mean an amount sufficient to reduce and most preferably prevent, a clinically significant deficit in the activity, function and response of the host. Alternatively, a therapeutically effective amount is sufficient to cause an improvement in a clinically significant condition in a host. As is appreciated by those skilled in the art, the amount of a compound may vary depending on its specific activity. Suitable dosage amounts may contain a predetermined quantity of active composition calculated to produce the desired therapeutic effect in association with the required diluent. In the methods and use for manufacture of compositions of the invention, a therapeutically effective amount of the active component is provided. A therapeutically effective amount can be determined by the ordinary skilled medical or veterinary worker based on patient characteristics, such as age, weight, sex, condition, complications, other diseases, etc., as is well known in the art. The administration of the pharmaceutically effective dose can be carried out both by single administration in the form of an individual dose unit or else several smaller dose units and also by multiple administrations of subdivided doses at specific intervals. Alternatively, the does may be provided as a continuous infusion over a prolonged period.

In the context of diagnostic use of the antibody polypeptides of the invention, a ‘pharmaceutically effective amount’, or ‘effective amount’, or ‘diagnostically effective’, as used herein, refers to that amount which provides a detectable signal for diagnosis, e.g. for in vivo imaging purposes.

The antibody polypeptides can be formulated at various concentrations, depending on the efficacy/toxicity of the polypeptide being used. For example, the formulation may comprise the active antibody polypeptide at a concentration of between 0.1 μM and 1 mM, more preferably between 1 μM and 500 μM, between 500 μM and 1 mM, between 300 μM and 700 μM, between 1 μM and 100 μM, between 100 μM and 200 μM, between 200 μM and 300 μM, between 300 μM and 400 μM, between 400 μM and 500 μM, between 500 μM and 600 μM, between 600 μM and 700 μM, between 800 μM and 900 μM or between 900 μM and 1 mM. Typically, the formulation comprises the active antibody polypeptide at a concentration of between 300 μM and 700 μM.

Typically, the therapeutic dose of the antibody polypeptide (with or without a therapeutic moiety) in a human patient will be in the range of 100 μg to 700 mg per administration (based on a body weight of 70 kg). For example, the maximum therapeutic dose may be in the range of 0.1 to 10 mg/kg per administration, e.g. between 0.1 and 5 mg/kg or between 1 and 5 mg/kg or between 0.1 and 2 mg/kg. It will be appreciated that such a dose may be administered at different intervals, as determined by the oncologist/physician; for example, a dose may be administered daily, twice-weekly, weekly, bi-weekly or monthly.

It will be appreciated by persons skilled in the art that the pharmaceutical compositions of the invention may be administered alone or in combination with other therapeutic agents used in the treatment of cancers, such as antimetabolites, alkylating agents, anthracyclines and other cytotoxic antibiotics, vinca alkyloids, etoposide, platinum compounds, taxanes, topoisomerase I inhibitors, other cytostatic drugs, antiproliferative immunosuppressants, corticosteroids, sex hormones and hormone antagonists, and other therapeutic antibodies (such as trastuzumab).

A seventh aspect of the invention provides an antibody or antigen-binding fragment thereof according to the first aspect of the invention for use in medicine.

A related eighth aspect of the invention provides an antibody or antigen-binding fragment thereof according to the first aspect of the invention for use in inducing cell death and/or inhibiting the growth and/or proliferation of pathological cells associated with a neoplastic disorder in a subject, or stem cells or progenitor cells thereof, wherein the cells express IL1RAP.

A further related ninth aspect of the invention provides an antibody or antigen-binding fragment according to the first aspect of the invention for use in the treatment and/or diagnosis of a neoplastic disorder in a subject, wherein the neoplastic disorder is associated with cells expressing IL1RAP.

By ‘treatment’ we include both therapeutic and prophylactic treatment of the patient. The term ‘prophylactic’ is used to encompass the use of an agent, or formulation thereof, as described herein which either prevents or reduces the likelihood of a neoplastic disorder, or the spread, dissemination, or metastasis of cancer cells in a patient or subject. The term ‘prophylactic’ also encompasses the use of an agent, or formulation thereof, as described herein to prevent recurrence of a neoplastic disorder in a patient who has previously been treated for the neoplastic disorder.

By “diagnosis” we include the detection of cancerous cells, either in vivo (i.e. within the body of a patient) or ex vivo (i.e. within a tissue or cell sample removed from the body of a patient).

By “a neoplastic disorder associated with cells expressing IL1RAP” we include such disorders wherein the pathological cells which are responsible, directly or indirectly, for the disorder express IL1RAP on the cell surface. It will be appreciated that the cells expressing IL1RAP may be cancer cells, e.g. tumour cells, per se. In addition, such cells include pathological stem cells (i.e. cancer stem cells, or CSCs) and progenitor cells which are responsible, directly or indirectly, for the development of a neoplastic disorder in an individual. Examples of CSCs are disclosed in Visvader & Lindeman, 2008, Nat Rev Cancer 8:755-768, the disclosures of which are incorporated herein by reference.

Alternatively, or in addition, the cells expressing IL1RAP may be associated indirectly with the neoplastic disorder, for example, they may mediate cellular processes required for the neoplastic cells to survive. The antibody agent of the invention may in this event target cells essential for the blood supply of the tumour (angiogenesis), the tumour stroma or cells inhibiting a beneficial immune response directed against the malignant cells (e.g. suppressive macrophages or T-cells).

Depending upon whether it is therapeutically desirable to kill the target cells expressing IL1RAP, an antibody or antigen-binding fragment according to the first aspect of the invention mau be used that it capable of inducing ADCC. For example, where the target cells IL1RAP are cancer cells (such as CML, AML, ALL, melanoma, lung cancer cells, etc) it may be advantageous for the antibody or antigen-binding fragment to be capable of inducing ADCC in order to eliminate such cells. However, it will be appreciated that a therapeutic benefit may also be achieved using an antibody or antigen-binding fragment that lacks ADCC activity, for example through inhibition of IL-1 (or IL-33) signaling leading to reduced angiogenesis in the vicinity of a tumour.

In one embodiment, the neoplastic disorder is a neoplastic haematologic disorder.

For example, the antibody or antigen-binding fragment thereof may be for use in the treatment and/or diagnosis of a neoplastic disorder selected from the group consisting of chronic myeloid leukemia (CML), myeloproliferative disorders (MPD), myelodysplastic syndrome (MDS), acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML).

In a further embodiment, the antibody or antigen-binding fragment thereof is for use in the treatment and/or diagnosis of a neoplastic disorder associated with the formation of solid tumours within the subject's body.

Thus, the antibody or antigen-binding fragment thereof may be for use in the treatment of a neoplastic disorder selected from the group consisting of prostate cancer, breast cancer, lung cancer, colorectal cancer, melanomas, bladder cancer, brain/CNS cancer, cervical cancer, oesophageal cancer, gastric cancer, head/neck cancer, kidney cancer, liver cancer, lymphomas, ovarian cancer, pancreatic cancer, and sarcomas.

In relation to the therapeutic and prophylactic aspects of the invention, it will be appreciated by persons skilled in the art that binding of the antibody polypeptide to IL1RAP present on the surface of the cells associated with the neoplastic disorder may lead to a modulation (i.e. an increase or decrease) of a biological activity of IL1RAP. However, such a modulatory effect is not essential; for example, the antibody polypeptides of the invention may elicit a therapeutic and prophylactic effect simply by virtue of binding to IL1RAP on the surface of the cells associated with the solid tumour, which in turn may trigger the immune system to induce cell death (e.g. by ADCC and/or by the presence within the agent of a cytotoxic/radioactive moiety).

By “biological activity of IL1RAP” we include any interaction or signaling event which involves IL1RAP on the cells associated with the neoplastic disorder. For example, in one embodiment the antibody polypeptide is capable of blocking binding of one or more co-receptors to IL1RAP (such as IL1R1, ST2, C-KIT and/or IL1RL2).

Such inhibition of the biological activity of IL1RAP by an antibody polypeptide of the invention may be in whole or in part. For example, the agent may inhibit the biological activity of IL1RAP by at least 10%, preferably at least 20%, 30%, 40%, 50%, 60%, 70%, 80% or 90%, and most preferably by 100% compared to the biological activity of IL1RAP in cells associated with the neoplastic disorder which have not been exposed to the antibody polypeptide. In a preferred embodiment, the antibody polypeptide is capable of inhibiting the biological activity of IL1RAP by 50% or more compared to the biological activity of IL1RAP in cells associated with the neoplastic disorder which have not been exposed to the antibody polypeptide.

Likewise, it will be appreciated that inhibition of growth and/or proliferation of the cells associated with the neoplastic disorder may be in whole or in part. For example, the antibody polypeptide may inhibit the growth and/or proliferation of the cells associated with the neoplastic disorder by at least 10%, preferably at least 20%, 30%, 40%, 50%, 60%, 70%, 80% or 90%, and most preferably by 100% compared to the growth and/or proliferation of cells associated with the neoplastic disorder which have not been exposed to the antibody polypeptide.

A tenth aspect of the invention provides use of an antibody or antigen-binding fragment thereof according to the first aspect of the invention in the preparation of a medicament for the treatment of a neoplastic disorder in a subject, wherein the neoplastic disorder is associated with cells expressing IL1RAP.

In a related aspect, the invention provides use of an antibody or antigen-binding fragment thereof according to the first aspect of the invention in the preparation of an agent for the diagnosis and/or prognosis of a neoplastic disorder in a subject, wherein the neoplastic disorder is associated with cells expressing IL1RAP. Thus, there is provided a diagnostic and/or prognostic agent for use in detecting cells (expressing IL1RAP) that are associated with a neoplastic disorder. The invention further provides the use of an IL1RAP-specific antibody or antigen-binding fragment thereof according to the first aspect of the invention in the preparation of a kit for diagnosing and/or prognosing a neoplastic disorder in a subject.

In one embodiment, the neoplastic disorder is a neoplastic haematologic disorder.

For example, the antibody or antigen-binding fragment thereof may be for use in the treatment and/or diagnosis of a neoplastic disorder selected from the group consisting of chronic myeloid leukemia (CML), myeloproliferative disorders (MPD), myelodysplastic syndrome (MDS), acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML).

In a further embodiment, the antibody or antigen-binding fragment thereof is for use in the treatment and/or diagnosis of a neoplastic disorder associated with the formation of solid tumours within the subject's body.

Thus, the antibody or antigen-binding fragment thereof may be for use in the treatment and/or diagnosis of a neoplastic disorder selected from the group consisting of prostate cancer, breast cancer, lung cancer, colorectal cancer, melanomas, bladder cancer, brain/CNS cancer, cervical cancer, oesophageal cancer, gastric cancer, head/neck cancer, kidney cancer, liver cancer, lymphomas, ovarian cancer, pancreatic cancer, and sarcomas.

An eleventh aspect of the invention provides a method for the treatment or diagnosis of a neoplastic disorder in a subject, comprising the step of administering to the subject an effective amount of an antibody or antigen-binding fragment thereof according to the first aspect of the invention, wherein the neoplastic disorder is associated with cells expressing IL1RAP.

In one embodiment, the neoplastic disorder is a neoplastic haematologic disorder.

to For example, the method may be for use in the treatment and/or diagnosis of a neoplastic disorder selected from the group consisting of chronic myeloid leukemia (CML), myeloproliferative disorders (MPD), myelodysplastic syndrome (MDS), acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML).

In a further embodiment, the method is for use in the treatment and/or diagnosis of a neoplastic disorder associated with the formation of solid tumours within the subject's body.

Thus, the method may be for use in the treatment of a neoplastic disorder selected from the group consisting of prostate cancer, breast cancer, lung cancer, colorectal cancer, melanomas, bladder cancer, brain/CNS cancer, cervical cancer, oesophageal cancer, gastric cancer, head/neck cancer, kidney cancer, liver cancer, lymphomas, ovarian cancer, pancreatic cancer, and sarcomas.

In a further embodiment, the antibody polypeptides and formulations of the invention may be used to treat patients or subjects who suffer from or are at risk of suffering a disease or condition susceptible to treatment with an inhibitor of IL-1 (or IL-33) signaling.

Thus, a twelfth aspect of the invention provides an antibody or antigen-binding fragment thereof according to the first aspect of the invention for use in the treatment of a disease or condition susceptible to treatment with an inhibitor of IL-1 (or IL_33) signaling.

Such conditions or disease states are well known in the art (see Dinarello et al., 2012, Nature Reviews 11:633-652 and Dinarello, 2014, Mol. Med. 20(suppl. 1):543-558)_ and include, but are not limited to, the following:

• • Rheumatoid arthritis, all types of juvenile arthritis including systemic onset juvenile idiopathic arthritis (SOJIA), osteoarthritis, familial cold auto-inflammatory syndrome (FCAS), Muckle-Wells disease, neonatal onset multi-system inflammatory disease (NOMID), familial Mediterranean fever (FMF), pyogenic arthritis pyoderma gangrenosum and acne (PAPA) syndrome, adult onset Still's disease, hyper IgD syndrome, type 2 diabetes mellitus, macrophage activation syndrome, TNF receptor-associated periodic syndrome, Blau disease, ankylosing spondylitis, Sweets disease, lupus arthritis, Alzheimer's disease, psoriasis, asthma, atherosclerosis, sarcoidosis, atopic dermatitis, systemic lupus erythematosus, bullous pemphigoid, type I diabetes mellitus, chronic obstructive pulmonary disease, Helicobacter pylori gastritis, inflammatory bowel disease (including ulcerative colitis and Crohn's disease), Hepatitis C, ischaemia-reperfusion injury, multiple sclerosis, Neisserial or pneumococcal meningitis, tuberculosis, Bechet's syndrome, septic shock, graft versus host disease, asthma, type I diabetes, Alzheimer's disease, atherosclerosis, adult T cell leukaemia, multiple myeloma, periodontitis, obesity and obesity-related diseases (for example, metabolic syndrome, cardiomegaly, congestive heart failure, varicose veins, polycystic ovarian syndrome, gastroesophageal reflux disease (GERD), fatty liver disease, colorectal cancer, breast cancer, uterine cancer, chronic renal failure, stroke and hyperuricemia), intervertebral disc disease, irritable bowel syndrome, Schnitzler syndrome, allergy/atopic dermatitis and gout.

Blockade of IL-1 signaling is also believed to beneficial in the treatment of myocardial infarction. An extensive clinical trial is currently seeking to confirm the efficacy of IL1 B antibody blockade (using Canakinumab) following myocardial infarction (the CANTOS trail; see Ridker et al., 2011, Am Heart Journal 162(4):597-605).

For such indications, it will be appreciated that a therapeutic benefit may also be achieved using an antibody or antigen-binding fragment that lacks ADCC activity, for example through inhibition of IL-1 (or IL-33) signaling associated with immune cells.

A thirteenth aspect of the invention provides the use of an antibody or antigen-binding fragment thereof according to the first aspect of the invention in the preparation of a medicament for the treatment of a disease or condition susceptible to treatment with an inhibitor of IL-1 (and/or IL-33 and/or IL-36) signaling.

A fourteenth aspect of the invention provides a method for the treatment of a disease or condition susceptible to treatment with an inhibitor of IL-1 (and/or IL-33 and/or IL-36) signaling in a subject, comprising the step of administering to the subject an effective amount of an antibody or antigen-binding fragment thereof according to the first aspect of the invention.

A fifteenth aspect of the invention provides a method for the ADCC-mediated treatment or augmentation of a disease or condition susceptible to treatment with an inhibitor of IL-1 (and/or IL-33 and/or IL-36) signaling in a subject, comprising the step of administering to the subject an effective amount of an antibody or antigen-binding fragment thereof according to the first aspect of the invention capable of inducing ADCC.

A sixteenth aspect of the invention provides an in vitro method for the detection of cancer cells in a subject, the method comprising:

• • (a) providing a sample of cells (e.g. white blood stem/progenitor cells or biopsy tissue) from a subject to be tested;
  • (b) optionally, extracting and/or purifying the cells present in the sample;
  • (c) contacting an antibody or antigen-binding fragment thereof according to the first aspect of the invention with cells present in the sample;
  • (d) determining whether the antibody polypeptide binds to the cells

wherein the binding of the antibody polypeptide to the cells is indicative of the presence of cancer cells in the tissue of a subject.

A seventeenth aspect of the invention provides an in vitro method for identifying a patient with cancer who would benefit from treatment with an antibody or antigen-binding fragment thereof according to the first aspect of the invention, the method comprising:

• • (a) providing a sample of cancer cells (e.g. white blood stem/progenitor cells or biopsy tissue) from a patient to be tested;
  • (b) optionally, extracting and/or purifying the cells present in the sample;
  • (c) contacting an antibody or antigen-binding fragment thereof according to the first aspect of the invention with cells present in the sample;
  • (d) determining whether the antibody polypeptide binds to the cells

wherein the binding of the antibody polypeptide to the cancer cells is indicative of a patient who would benefit from treatment with an antibody or antigen-binding fragment thereof according to the first aspect of the invention.

Persons skilled in the art will appreciate that there are many ways to perform such an assay. For example, the immunoassay could be either homogeneous or, more preferably, heterogenous. The assay could also be performed in either a competitive or, more preferably, a non-competitive format.

In one embodiment, IL1RAP expression on blood samples (leukemia) or biopsies (solid tumours) from patients is measured using flow cytometry or immunohistochemistry, with expression above a threshold value being indicative of a patient who would benefit from treatment with an antibody or antigen-binding fragment thereof according to the first aspect of the invention.

In preferred embodiments of the above in vitro methods, step (d) is performed by flow cytometry or ELISA. However, any assay suitable for detecting antibody-antigen interactions in vitro may be used.

An eighteenth aspect of the invention provides a method for treating a patient with cancer, the method comprising administering to a subject identified as having cancer using a method according to the sixteenth or seventeenth aspects of the invention a therapeutic agent effective in the treatment of said cancer. In one embodiment, the example therapeutic agent is an antibody polypeptide according to the first aspect of the invention.

In one embodiment, the method comprises:

• • (a) arranging for a sample of cells (e.g. white blood stem/progenitor cells or biopsy tissue) from a subject to be tested for the presence of cancer cells expressing IL1RAP above a threshold criteria using a method according to the sixteenth or seventeenth aspect of the invention;
  • (b) selecting for treatment subjects whose sample of cells tested in step (a) contains cancer cells with IL1RAP expression above a threshold criteria; and
  • (c) administering to the subject selected in step (b) a therapeutic agent effective in the treatment of said cancer, for example an antibody polypeptide according to the first aspect of the invention.

It will be appreciated by persons skilled in the art that cancer cells expressing IL1RAP may be identified using a probe capable of binding specifically to either:

• • (a) an IL1RAP polypeptide (e.g. an antibody or antigen-binding fragment thereof according to the invention); or
  • (b) an IL1RAP polynucleotide transcript/mRNA (e.g. using an oligonucleotide probe complementary in sequence to a region of the IL1RAP polynucleotide transcript/mRNA).

Methods for performing such testing are well known in the art.

In a related embodiment, the method comprises:

• • (a) obtaining a sample of cells (e.g. white blood stem/progenitor cells or biopsy tissue) from a subject
  • (b) testing said cells for the presence of cancer cells expressing IL1RAP above a threshold criteria using a method according to the sixteenth or seventeenth aspect of the invention;
  • (c) selecting for treatment subjects whose sample of cells tested in step (b) contains cancer cells with IL1RAP expression above a threshold criteria; and
  • (d) administering to the subject selected in step (c) a therapeutic agent effective in the treatment of said cancer, for example an antibody polypeptide according to the first aspect of the invention.

Optionally, steps (a) and (b) of the above embodiments may be repeated following a first period of treatment (for example, after one month) to determine is the number of cancer cells with IL1RAP expression above a threshold criteria has reduced. If an inadequate reduction (e.g. no reduction) is observed, then the dose of therapeutic agent effective in the treatment of said cancer is increased for a subsequent treatment round. If no cancer cells with IL1RAP expression above a threshold criteria are detected, the treatment may be terminated.

A nineteenth aspect of the invention provides a in vitro diagnostic method for identifying a patient with cancer who would benefit from treatment with an antibody or antigen-binding fragment thereof of the invention, said method comprising the steps of:

• • (a) contacting in vitro a sample of cells (e.g. white blood stem/progenitor cells or biopsy tissue) from a subject to be tested with a molecular probe capable of binding specifically to an IL1RAP polypeptide, or to an IL1RAP polynucleotide transcript, said probe being covalently bound to a moiety capable of emitting photons; and
  • (b) detecting photons emitted from said moiety and forming an image of the sample, wherein localised emission of photons from said moiety is indicative of said subject being a patient with cancer who would benefit from treatment with an antibody or antigen-binding fragment thereof of the invention.

Preferences and options for a given aspect, feature or parameter of the invention should, unless the context indicates otherwise, be regarded as having been disclosed in combination with any and all preferences and options for all other aspects, features and parameters of the invention. For example, in one embodiment the invention provides an intact IgG1 antibody comprising a heavy chain variable region having the amino acid sequence of SEQ ID NO:1 and a light chain variable region having the amino acid sequence of SEQ ID NO:2 for use in the treatment of AML.

The listing or discussion of an apparently prior-published document in this specification should not necessarily be taken as an acknowledgement that the document is part of the state of the art or is common general knowledge.

The use of the word “a” or “an” when used in conjunction with the term “comprising” in the claims and/or the specification may mean “one,” but it is also consistent with the meaning of “one or more,” “at least one,” and “one or more than one.”

These, and other, embodiments of the invention will be better appreciated and understood when considered in conjunction with the above description and the accompanying drawings. It should be understood, however, that the above description, while indicating various embodiments of the invention and numerous specific details thereof, is given by way of illustration and not of limitation. Many substitutions, modifications, additions and/or rearrangements may be made within the scope of the invention without departing from the spirit thereof, and the invention includes all such substitutions, modifications, additions and/or rearrangements.

The following drawings form part of the present specification and are included to further demonstrate certain aspects of the present invention. The invention may be better understood by reference to one or more of these drawings in combination with the detailed description of specific embodiments presented herein.

FIG. 1. Binding to human IL-1RAP of the exemplary antibodies CAN01 and CAN03 in an indirect ELISA.

FIG. 2. Binding of exemplary antibodies of the invention (CAN01 and CAN03) to human CML cells. The graph shows the WI value for KU812 cells stained with IL1RAP-targeting monoclonal antibodies at a concentration of 0.1 μg/mL.

FIG. 3. Ability of exemplary antibody CAN03 to block IL-1b signaling.

FIGS. 4A-4D. In vitro ADCC assay shows that exemplary antibody CAN01 and CAN03 induces specific cell killing of CML cells. (FIG. 4A) KU812, LAMA84, and BV173 cells were specifically killed by addition of 10 μg/mL CAN01. (FIG. 4B) The cell killing mediated by exemplary antibodies CAN01 and CAN03 is dose dependent as shown on BV173 target cells. (FIG. 4C) Cell killing of primary cells from two CML blast crisis patients was induced by 1 μg/mL CAN01. (FIG. 4D) Cells from a third CML blast crisis patient carrying the T315I mutation were sensitive to the ADCC effect mediated by CAN01. Each experiment was performed at least twice with NK cells from different donors, and the presented data shows one representative experiment from each.

FIG. 5. In vitro ADCC assay showing that the exemplary antibodies CAN01 and CAN03 are efficient in inducing specific cell killing of melanoma cells (SKMEL5 cell line). Already at 1 μg/mL, CAN01 and CAN03 show a high specific target cell killing. The experiment was performed at least twice with NK cells from different donors, and the presented data shows one representative experiment.

FIGS. 6A-6C. (FIG. 6A) Confocal images (one optical section, about 0.9 μm thick) showing LAMA cells incubated for 2 hours with CAN01-AF488 conjugated antibodies on ice, or at 37° C. for 2 hours, or been incubated with CAN01-AF488 conjugated antibodies for 16 hours at 37 C°. A clearly defined antibody binding to the cell membrane of the majority of cells can be observed after 2 hours incubation on ice (“Ice 2 h)”. After incubation for 2 hours with CAN01-AF488 conjugated antibodies at 37° C., in addition to membrane binding, antibodies have started to enter the cells (internalization) and are now localized also in the cytosol. After 16 hours of incubation at 37° C., the cell membrane binding is still present and to the antibody internalization has produced accumulation of CAN01-AF488 antibodies in the majority of cells. Scale bar (right image) represents 20 μm in all images. (FIG. 6B) Confocal images (one optical section, about 0.9 μm thick) showing LAMA cells incubated for 2 hours with CAN03-AF488 conjugated antibodies on ice, or at 37° C. for 2 hours, or been incubated with CAN03-AF488 conjugated antibodies for 16 hours at 37 C°. A clearly defined antibody binding to the cell membrane of the majority of cells can be observed after 2 hours incubation on ice (“Ice 2 h)”. After incubation for 2 hours with CAN03-AF488 conjugated antibodies at 37° C., in addition to membrane binding, antibodies have started to enter the cells (internalization) and are now localized also in the cytosol. After 16 hours of incubation at 37° C., the cell membrane binding is still present and the antibody internalization has produced accumulation of CAN03-AF488 antibodies in the majority of cells. Scale bar (right image) represents 20 μm in all images. (FIG. 6C) Control for the CAN03-specific binding and internalization: The confocal images (one optical section, about 0.9 μm thick) show LAMA cells incubated with AF488 conjugated isotype control antibody on ice or at 37° C. for 2 hours, or at 37C° for 16 hours. The isotype control antibody showed no specific binding at any of these conditions. Minor binding to cellular debris and necrotic cells was noted. Scale bar (right image) represents 20 μm in all images.

FIGS. 7A-7E. Treatment with CAN01 significantly reduces the leukemia burden. (FIG. 7A) The frequency of leukemic cells in peripheral blood was lower in mice treated with exemplary antibody CAN01 compared to isotype control at day 36 after transplantation (0.10% vs. 0.69%, p<0.0043). (FIG. 7B) The platelet (PLT) count were lower with isotype than with CAN01 (p=0.015). (FIG. 7C) At day 62 the mean frequency of leukemic cells in peripheral blood was 46.5% in isotype treated mice but only 3.8% with CAN01. (FIG. 7D) At time of sacrifice the frequency of leukemic cells in the spleen was reduced with CAN01 (17.2% vs. 49.7%; p=0.0052). (FIG. 7E) The frequency of leukemic cells in bone marrow was lower in mice treated with CAN01 compared to isotype control (5.0% vs. 59.5%; p=0.0001).

FIGS. 8A-8D. Treatment with CAN01 prolongs survival and reduces the leukemia burden. (FIG. 8A) The median survival for isotype treated mice was 37 days and 58 days for mice treated with CAN01 (p<0.0001) (FIG. 8B) At time of sacrifice the frequency of leukemic cells in the bone marrow was reduced with CAN01 (29.2% vs. 55.9%; p=0.020). (FIG. 8C) The mean frequency of leukemic cells in was lower in mice treated with CAN01 compared to isotype control (31.7% vs. 43.1%). (FIG. 8D) Mice treated with CAN01 had significantly smaller spleens than mice given isotype control (60 mg vs. 97 mg; p=0.032))

FIG. 9. Treatment with CAN01 significantly reduces the leukemia burden in mice transplanted with primary human AML cells. The mean frequency of leukemic cells in bone marrow was 0.001% in mice treated with CAN01 and 0.126% in mice given control antibody.

FIGS. 10A-10C. Effects of CAN01, CAN03 and Isotype control on HEK-Blue IL-33/IL 18 cells stimulated with (FIG. 10A) human IL-1α, (FIG. 10B) human IL-1β, and (FIG. 10C) human IL-33. Two experiments were performed with duplicate samples, and represented as the individual values plus the mean value as three individual data points.

FIGS. 11A-11C. Effects of CAN01, CAN03 and Isotype control on HEK-Blue IL-33/IL 1β cells stimulated with (FIG. 11A) murine IL-1α, (FIG. 11B) murine IL-1β, and (FIG. 11C) murine IL-33,

1β cells. Two experiments were performed with duplicate samples, and represented as the individual values plus the mean value as three individual data points.

EXAMPLES

A. Binding Affinity of Exemplary Antibodies of the Invention for IL1RAP Protein

(i) Biacore Study—Anti-IL1RAP Antibodies of Murine Origin

Materials & Methods

Goat anti-mouse IgG was immobilized on a CM5 chip according to the technical manual of capture kit and standard operation principle of BIAcore T200 (Biacore Life Sciences, GE Healthcare Europe GmbH, Uppsala, Sweden).

The binding analysis cycle consisted of three steps: (i) capture of the ligand on the chip surface by immobilized anti-mouse antibody; (ii) binding of the analyte to the captured ligand; and (iii) dissociation of bound analyte.

The capture molecule surface was regenerated after each binding cycle using the manufacturer's recommended conditions.

All binding cycles were run at 25° C.

After five cycles of start-up, each antibody (100 nM) was injected at a flow rate of 30 μl/min, for 120 s, at the start of the cycle; then the analyte (100 nM) was injected at a flow rate of 30 μl/min, for 120 s, followed by monitoring the dissociation phase for 300 s.

Two exemplary antibodies of the invention (CAN01 and CAN03) were tested.

Results & Conclusions

Results are shown in Table 2 below:

TABLE 2
Measurement of Kon, Koff and KD
	Antibody	ka (1/M · s)	kd (1/s)	KD (M)
	CAN01	2.34E+05	3.35E−04	1.43E−09
	CAN03	2.26E+05	7.25E−05	3.21E−10

(ii) ELISA Study—Anti-IL1RAP Antibodies of Murine Origin

Materials & Methods

An indirect ELISA assay was performed. All samples were analysed in duplicate. Nunc-MaxiSorp 96 Micro Well™ Plates were coated with 100 ng of recombinant hIL1RAP 21-367 (100 μl/well) diluted in 0.01M PBS, pH 7.4, and incubated overnight at 4° C. Plates were washed with ELISA washing buffer (0.01M PBS, 0.05% Tween 20, pH 7.4) followed by a blocking step using 150 μl/well of ELISA blocking solution (PBS, 0.5% BSA, 0.05% Tween 20, pH 7.4). After 1 h incubation at room temperature (RT) on agitation the plates were washed again using ELISA washing buffer. Samples were diluted in three fold serial dilution (ranging from 1000 ng/ml to 0.5 ng/ml) in ELISA blocking solution and then transferred to the ELISA plate, 100 μl/well. Plates were incubated at RT for 1 h on agitation and then washed with ELISA washing solution. 100 μl/well of rabbit anti-mouse IgG conjugated to Alkaline Phosohatase (DAKO, 1:1000) was added and incubated 1 hour at RT on agitation. The plates were washed followed by addition of substrate (4-Nitrophenyl phosphatise disodium salt hexahydrate, SIGMA, 1 mg/ml), 100 μl/well. The plates were thereafter incubated at RT on agitation and absorbance at 405 nm measured consecutively for 30 min. Absorbance at 0 min was taken as background signal.

Results & Conclusions

Results are shown in FIG. 1

The exemplary antibodies of the invention, CAN01 and CAN03, were both found to possess a high binding signal for human IL1RAP.

B. Flow Cytometry Study of the Binding of Exemplary Antibodies of the Invention to IL1RAP-Expressing Cells

Materials & Methods

Chronic myeloid leukemia (CML) cell line KU812 cells were stained with antibodies raised against IL1RAP or a relevant isotype control. For detection, a secondary anti-mlg-APC was used.

Two exemplary antibodies of the invention (CAN01 and CAN03) were tested along with five comparator anti-IL1RAP antibodies (CAN02, CAN05, CAN07, CAN08 and CAN09). An isotype negative control antibody was also included.

Results & Conclusions

Staining of IL1RAP-expressing KU812 leukemia cells reveals a higher mean fluorescence intensity (MFI) for CAN01 and CAN03 compared to the isotype control and other comparator antibodies targeting IL1RAP (FIG. 2).

C. Epitope/Domain Mapping of Exemplary Antibodies of the Invention

Materials & Methods

In order to understand where the different antibody clones bind on the IL1RAP, a structural analysis of the protein was performed revealing that the extracellular part of the receptor could be divided into three distinct domains hereafter referred to as domains 1, 2 and 3 (D1, D2, D3) (see Wang et al., 2010, Nature Immunology, 11:905-912, the disclosures of which are incorporated herein by reference). In order to determine the domain-binding pattern for the different antibody clones, a series of receptor constructs were generated and binding to these tested in an ELISA assay.

An indirect ELISA assay was performed. All samples were analysed in duplicate. Nunc-MaxiSorp 96 Micro Well™ Plates were coated with 100 ng of Rec hIL1RAP Domain123 (aa21-367) (positive control), Rec hIL1RAP Domain12 (aa21-234), Domain1 (aa21-134) or Rec hIL1RAP Domain3 (aa235-367) (100 μl/well) diluted in 0.01M PBS, pH 7.4, and incubated overnight at 4° C. Plates were washed with ELISA washing buffer (0.01M PBS, 0.05% Tween 20, pH 7.4) followed by a blocking step using 150 μl/well of ELISA blocking solution (PBS, 0.5% BSA, 0.05% Tween 20, pH 7.4). After 1 h incubation at room temperature (RT) on agitation the plates were washed again using ELISA washing buffer. CAN01, CAN03, CAN05, CAN07, CAN08 and KMT-1 (positive control) were diluted in three fold serial dilution (ranging from 1000 ng/ml to 0.5 ng/ml) in ELISA blocking solution and then transferred to the ELISA plate, 100 μl/well. Plates were incubated at RT for 1 h on agitation and then washed with ELISA washing solution. 100 μl/well of rabbit anti-mouse IgG conjugated to Alkaline Phosphatase (DAKO, 1:1000) was added and incubated 1 hour at RT on agitation. The plates were washed followed by addition of substrate (4-Nitrophenyl phosphatise disodium salt hexahydrate, SIGMA, 1 mg/ml), 100 μl/well. The plates were thereafter incubated at RT on agitation and absorbance at 405 nm measured consecutively for 30 min. Absorbance at 0 min was taken as background signal.

Two antibodies of the invention (CAN01 and CAN03) were tested along with five comparator anti-IL1RAP monoclonal antibodies (CAN02, CAN05, CAN07, CAN08, together with a polyclonal anti-IL1RAP antibody (KMT-1) as a positive control).

Results & Conclusions

The exemplary antibodies of the invention, CAN01 and CAN03, were found to bind within domain 3 of IL1RAP.

The domain mapping data can be found summarized in the Table 3 below.

TABLE 3
Epitope mapping of exemplary anti-IL1RAP antibody clones.
	Domain123	Domain12	Domain1	Domain3	Suggested
Clone	(aa21-367)	(aa21-234)	(aa21-134)	(aa235-367)	epitope
CAN03	+			+	D3
CAN05	+	+	+		D1
CAN07	+			+	D3
CAN08	+			+	D3
CAN01	+			+	D3
CAN02	+				nd*
KMT-1	+	+	+	+	polyclonal
nd* = not determined as epitope mapping data could not clearly identify specific domain for these constructs, which may be attributed to binding to a structural epitope containing sequence elements from more than one domain, e.g. D2-D3 junction.

D. Specificity/Cross-Reactivity of Exemplary Antibodies of the Invention

Materials & Methods

An important feature of a good lead candidate antibody is that it cross-reacts with equal or near-equal potency to the homologous protein in a relevant toxicology species. According to the general regulatory guidelines, binding to one rodent and one non-rodent would be the preferred scenario, but for antibodies this is rarely the case, and instead many labs struggle to identify any relevant toxicology species except for primates.

For the present study, cross reactivity to non-human primates like Macaca mulatta (rhesus) or Macaca fascicularis (cynomolgus) was expected since the IL1RAP protein in these species share 99% homology to the human IL1RAP protein.

A number of potential lead antibodies were selected and tested for binding to recombinant M. fascicularis ILI RAP (aa21-367) in an ELISA assay.

Two antibodies of the invention (CAN01 and CAN03) were tested along with six comparator anti-IL1RAP monoclonal antibodies (CAN02, CAN07, CAN08, CAN09, Mab676 from R&D, and a polyclonal anti-IL1RAP antibody (KMT-1).

Results & Conclusions

Surprisingly, several of the comparator anti-IL1RAP antibodies tested were found not to cross-react with cynomolgus IL1RAP, amongst them the commercial reference antibody mAb676 from R&D, Table 4.

TABLE 4
Binding to cynomolgus IL1RAP
             Binding to rec. M. fascicularis
Clone        IL1RAP (OD405)
CAN01        0.324
CAN02        0.014
CAN09        0.022
CAN03        0.870
CAN07        0.111
CAN08        0.375
mAb676 (R&D) 0.037
KMT-1        0.481
(Values in bold denotes clones identified to cross-react with IL1RAP from M. fascicularis)

E. Inhibition of IL-1 Signaling by Exemplary Antibody of the Invention

(i) Effect in HEK-Blue Cell Line

Materials & Methods

As IL1RAP is a functional part of the IL-1 receptor complex, antibodies binding to IL1RAP may also inhibit IL-1 signaling. Since a number of tumour cell types have been shown to use IL-1 as a growth factor, this may be an important additional mechanism for mediating anti-tumour effects.

In order to test for the capability of potential lead candidate antibodies to block IL-1 signaling, an IL-1 dependent reporter gene assay was set up. HEK-Blue cells (InvivoGen) respond to IL-1 signaling by the release of alkaline phosphatase that can be quantified by a colorometric assay. To test the inhibitory capacity of the lead candidates HEK-Blue cells were plated at 50 000 cells/well and incubated with the test antibodies 30 minutes prior to stimulation with IL-1β. The cells were then incubated at 37° C. o/n before measuring the amount of alkaline phosphatase released. Antibodies were also tested for potential agonistic effects by incubating the cells in the presence of a high concentration of antibody (10 mg/ml) in the absence of additional stimuli. Any IL-1R agonistic effects would thus be recorded as a release of alkaline phosphatase.

One antibody of the invention (CAN03) was tested along with an isotype negative control antibody.

Results & Conclusions

As depicted in FIG. 3, the exemplary antibody CAN03 induced a pronounced inhibition of IL-1 signaling. The tested candidate showed no agonistic effect.

F. ADCC Effect of Exemplary Antibodies of the Invention in Chronic Myeloid Leukemia (CML) Cell Lines

Materials & Methods

Chronic myeloid leukemia (CML) cell lines KU812, LAMA84 and BV173, or primary cells from three patients with CML in blast crisis were used as target cells in the in vitro antibody dependent cellular cytotoxicity (ADCC) assay. Briefly, target cells were labelled with PKH26 (Sigma-Aldrich, St Louis, Mo.) according to manufacturer's instructions, and seeded into a 96-well plate at a density of 5,000-10,000 cells per well. Subsequently, the exemplar antibody of the invention, CAN01, or isotype control antibody was added to wells in different concentrations and incubated for 30 min before 100,000 NK effector cells were added to each well. NK-cells were extracted from healthy volunteers after informed consent by using an NK-cell negative cell isolation kit according to manufacturer's instructions (Miltenyi Biotech, Bergisch Gladbach, Germany). A non-specific human IgG1 antibody was used as an isotype negative control in the experiments (Eureka Therapeutics, Emeryville, Calif.). The degree of cell death was assessed by detection of 7-AAD positive cells using a FACS CANTO flow cytometer (BD). Each experiment was performed at least twice with NK cells from different donors.

Results & Conclusions

The in vitro ADCC assay shows that the exemplary antibody of the invention, CAN01, directs NK-cells to kill CML cell lines KU812, LAMA84 and BV173 to a higher degree than the isotype control (FIG. 4A). A dose titration of CAN01 and CAN03 using BV173 target cells shows that the effect on cell killing is dose dependent with a higher degree of cell killing with increasing concentrations (FIG. 4B). Chronic myeloid leukemia that has progressed into blast crisis display only transient effect to treatment with tyrosine kinase inhibitors and thus imposes a major treatment problem. The ADCC assay with primary cells from two individual CML blast crisis patients shows that these cells were sensitive to the cellular cytotoxicity induced by CAN01 and NK-cells (FIG. 4C). In addition, primary cells from a third CML blast crisis patient harbouring the T315I mutation that cause resistance to several tyrosine kinase inhibitors display similar sensitivity (FIG. 4D). Altogether, the experiments show that CAN01 has the ability to direct NK-cells to specific cell killing of CML cell lines as well as primary blast crisis CML cells, and that the cytotoxic effect induced by CAN01 is dose dependent.

G. ADCC Effect of Exemplary Antibodies of the Invention in Melanoma Cell Lines

Materials & Methods

The malign melanoma cell line SKMEL-5 was used as a target for in vitro antibody dependent cellular cytotoxicity (ADCC) assay. Briefly, target cells were labelled with PKH26 (Sigma-Aldrich, St Louis, Mo.) according to manufacturer's instructions, and seeded into a 96-well plate at a density of 5,000-10,000 cells per well. Subsequently, the test antibody or isotype control antibody were added to wells in different concentrations and incubated for 30 min before 100,000 NK effector cells were added to each well. NK-cells were extracted from healthy volunteers after informed consent by using an NK-cell negative cell isolation kit according to manufacturer's instructions (Miltenyi Biotech, Bergisch Gladbach, Germany). A non-specific human IgG1 antibody was used as control in the experiments (Eureka Therapeutics, Emeryville, Calif.). The degree of cell death was assessed by detection of 7-AAD positive within PKH26 positive cells using a FACS CANTO flow cytometer (BD). Each experiment was performed at least twice with NK cells from different donors.

Results & Conclusions

The in vitro ADCC assay showed that CAN01 and CAN03 direct NK-cells to killing of the SKMEL-5 cell line to a much higher degree than a matching isotype control (FIG. 5).

H. Internalisation of Exemplary Antibodies of the Invention

Materials & Methods

Cells and Culture Conditions: LAMA-84 cells, a cell-line established from a patient with chronic myeloid leukemia in blast crisis, were obtained from DSMZ (Braunschweig, Germany) and cultured according to the recommendation by the supplier. Briefly, cells were cultured in RPMI 1640 with 10% FBS, 1% Glutamine and 1% Penicillin/Streptomycin in 5% CO₂, 37° C. Cell cultures were split to a density of 0.5×10⁶ cells/ml every 2-3 days. Cells were used for up to 12 passages after they were received from DSMZ.

Cells from the suspension cell-line LAMA-84 were washed once in phosphate buffered saline (PBS) supplemented with 1% Bovine serum albumin (BSA) and resuspended in PBS-BSA supplemented with 5% human AB+ serum from Sigma and incubated for 5 minutes at room temperature (RT). The AlexaFluor488 (AF488) labelled IL-1RAP selective antibodies CAN01, CAN03 or isotype matched control antibody, was added to a final concentration of 10 μg/ml. Cells were placed (incubated) on ice or at 37° C. for 2 or 16 hours.

For the image analysis with confocal microscopy (LSM 510 Meta Zeiss confocal microscope), cells were washed twice in PBS-1% BSA, were briefly spun down followed by resuspension in 3% paraformaldehyde (in PBS) fixation for 20 minutes (at)4 C°. Cells were then spun down, resuspended in PBS containing 0.001% Triton X-100 (PBS-TX) and a nuclear marker (DAPI), and were let to incubate for 5 minutes at RT. After a brief centrifugation cells were resuspended in PBS-TX and placed in glass-bottomed microscope wells. Cells were then let to adhere for one hour. Image data were collected via confocal scanning of cells providing high-resolution images of AlexaFluor488 fluorescence in thin optical sections through the centre of cells (depicted by nuclear marker). Further analyses of antibody binding to cell membrane and/or internalized antibodies were performed via software image analyses (Zeiss Zen2010).

Results & Conclusions

The structural relation of CAN01 and CAN03 binding to the cell membrane and its capacity to enter the cells (“internalize”) was demonstrated with high resolution imaging data recorded by means of confocal laser scanning microscopy, and by image analyses of this data.

Image data representations are shown in FIG. 6.

I. Therapeutic Efficacy In Vivo of an Exemplary Antibody of the Invention

Materials & Methods

Unconditioned NOD/SCID mice were engrafted with lethal doses of MA9Ras cells, previously generated by transformation of human umbilical cord blood CD34⁺ cells by retroviral integration of cDNAs directing the expression of an MLL/AF9 fusion and an activated NRAS gene. Leukemic mice were treated with the exemplary CAN01 antibody targeting IL1RAP, or a corresponding isotype control antibody. The antibodies were administered by intraperitoneal injections twice weekly throughout the experiment with first treatment given day three after transplantation. Each dose of antibody was 500 μg, except for the first that was given as a bolus of 1000 μg. Mice were sacrificed upon signs of severe disease as judged by hunchback, untidy fur, and decreased mobility, or due to solid tumours.

Results & Conclusions

Immunodeficient mice were engrafted with human leukemic cells and treated with CAN01, a monoclonal antibody targeting IL1RAP. The frequency of leukemic cells in peripheral blood was significantly reduced at day 35 after transplantation, and the platelet counts remained normal in mice given CAN01 compared to isotype control antibody indicating a more functional haematopoiesis (FIG. 7A-B). At 62 days after transplantation the isotype treated mice had a high frequency of leukemic cells in peripheral blood (FIG. 7C). CAN01 treatment resulted in a significant reduction of leukemic cells in spleen and bone marrow (FIG. 7D-E). We conclude that anti-IL1RAP immunotherapy reduces human leukemia in peripheral blood, bone marrow, and spleen, in the MA9Ras xenograft model. The results support anti-IL1RAP immunotherapy as a new promising therapeutic strategy for AML.

J. Therapeutic Efficacy In Vivo of an Exemplary Antibody of the Invention

Materials & Methods

Unconditioned NOD/SCID mice were engrafted with BV173 CML cells, which harbour the BCR/ABL fusion gene. Leukemic mice were treated with the exemplary CAN01 antibody targeting IL1RAP, or a corresponding isotype control antibody. The antibodies were administered by intraperitoneal injections twice weekly for a maximum of 13 doses, with first treatment given day two and the last one day 45 after transplantation. Each dose of antibody was 500 μg, except for the first that was given as a bolus of 1000 μg. Mice were sacrificed upon signs of severe disease as judged by hunchback, weight loss, and decreased mobility.

Results & Conclusions

Immunodeficient mice were engrafted with human CML cells and treated with CAN01, a monoclonal antibody targeting IL1RAP. Mice given isotype control had a median survival of 37 days (range 33-38 days) whereas mice treated with CAN01 survived significantly longer (median 51 days), despite that the last treatment was administered at day 45 (FIG. 8A). Two CAN01 treated mice were still alive and apparently healthy at sacrifice day 101 after transplantation. CAN01 treatment resulted in a significant reduction of leukemic cells in the bone marrow (FIG. 8B). In the spleen there was a trend towards reduced leukemic frequency with CAN01 (FIG. 8C). Mice treated with CAN01 had significantly smaller spleens than isotype treated mice (FIG. 9D). We conclude that anti-IL1RAP immunotherapy prolongs survival and reduces human leukemia in the BV173 xenograft model. The results support anti-IL1RAP immunotherapy as a new promising therapeutic strategy for CML.

K. Therapeutic Efficacy In Vivo of an Exemplary Antibody of the Invention

Materials & Methods

Mononuclear cells were isolated from a bone marrow aspirate taken from an AML patient at diagnosis. The cells were transplanted by intravenous injection into unconditioned NOD/SCID mice. Starting three days after transplantation, mice were treated with anti-IL1RAP CAN01 or a corresponding mlgG2a isotype control antibody. The antibodies were administered by intraperitoneal injections twice weekly throughout the experiment. Each dose of antibody was 100 μg, except for the first that was given as a bolus of 500 μg. Mice were sacrificed 28 days after transplantation, and the bone marrow was analysed for frequency of human leukemic cells as detected by expression of CD45 and CD33 on flow cytometry.

Results & Conclusions

Immunodeficient mice were engrafted with primary human AML cells and treated with CAN01, a monoclonal antibody targeting IL1RAP. At sacrifice 28 days after transplantation, the frequency of leukemic cells in bone marrow was significantly reduced with CAN01 compared to isotype control (0.001% vs. 0.126%, p<0.0001; FIG. 9). We conclude that anti-IL1RAP immunotherapy reduces leukemia in bone marrow in mice engrafted with primary human AML cells. The results add strength to anti-IL1RAP immunotherapy as a new promising therapeutic strategy for AML.

L. In Vitro IL1RAP Dependent Blocking of Human IL-1α-, IL-1β- and IL-33-Mediated Signaling in HEK-Blue IL-33/IL-1β cells. Potency of antibodies CAN01 and CAN03.

The following experiments were performed to determine whether two exemplary antibodies of the invention (CAN01 and CAN03) were able to inhibit IL-1alpha and beta dependent signaling in the reporter gene assay using HEK-Blue IL-33/IL-1β cells.

Materials

Preparation of Antibodies

Exemplary antibodies of the invention (CAN01 and CAN03) together with an isotype control (mlgG2a) were provided by Innovagen AB (Lund, Sweden).

All antibodies were diluted in PBS for testing. Working solutions for reporter gene assay, HEK-Blue IL-33/IL-1β were made in PBS at 20 times at the final assay concentration. The final assay volume was 200 μl (containing 10 μl antibody or diluent (PBS)+180 μl cells+10 μl ligand) Final assay concentrations of antibodies were as follows; 100 to 0.01 nM (by serial dilutions in 3-fold dilutions steps).

Preparation of Human Ligands (IL-1α, IL-1β and IL-33)

Human ligands, IL-1α, IL-1β and IL-33 were diluted in PBS to a stock concentration of 10 μg/mL. Stock concentrations of 10 μg/mL of the ligands were stored in aliquots at −80° C. until use. For the reporter gene assay, the ligands were used at a final concentration of 0.3 ng/mL, the concentration that gave 70-80% of the maximal effect in the assay as determined in a pre-test experiment.

Dilution of Ligands to Final Assay Concentration

• • Stock of ligands 10 μg/mL was diluted 1:100 (2 μl+198 μl Selection medium, see below)=100 ng/mL.
  • 100 ng/mL was diluted 1:16.67 (150 μl+2350.5 μl Selection medium, see below)=6 ng/mL.
  • 6 ng/mL was diluted 1:20 in the assay; 10 μl of LPS 6 ng/mL+190 μl cells and compound/well to yield a final concentration of 0.3 ng/mL.

Cell Line

HEK-Blue IL-33/IL-1β cells, generated by stable transfection of HEK-Blue™ IL-1β cells with the IL1RL1, were used as IL-33/IL-1β sensor cells (Cat no. hkb-IL-33, InvivoGen, San Diego, US).

Methods

Study Design

Stock solutions of CAN01, CAN03, and Isotype control were prepared in PBS. Working solutions for reporter gene assay, HEK-Blue IL-33/IL-1β were made in PBS at 20 times at the final assay concentration. The final assay volume was 200 μl (containing 10 μl antibody or diluent (PBS)+180 μl cells+10 μl ligand). Final assay concentrations of antibodies were as follows; 100 to 0.01 nM (by serial dilutions in 3-fold dilutions steps. In control wells (stimulated/unstimulated cells) antibodies were replaced by 10 μl PBS.

Culturing and Stimulation of HEK-Blue IL-33/IL-1/3 Cells

As IL1RAP is a functional part of the IL-1 receptor complex, antibodies binding to IL1RAP have the potential to inhibit IL-1 signaling. Since tumour cells have been reported to use IL1RAP dependent ligands such as IL-1α, IL-1β and IL-33 as a growth factor, blocking this signal may provide an important mechanism for mediating anti-tumour effects (either separately or combined with an ADCC effect). In order to test for the capability of antibodies to block IL-1 signaling, an IL-1 dependent reporter gene assay was set up. HEK-Blue IL-33/IL-1β cells (InvivoGen) respond to IL-1 signaling by the release of alkaline phosphatase that can be quantified by a colorimetric assay. To test the inhibitory capacity of the lead candidates HEK-Blue cells were plated at 50 000 cells/well and incubated with the test antibodies 45 minutes prior to stimulation with IL-1α, IL-1β, and IL-33 in a final concentration of 0.3 ng/ml for each ligand. Final assay concentrations of antibodies were 100 nM-0.01 nM. In control wells, antibodies were replaced by PBS. The cells were incubated at 37° C. o/n before measuring the amount of alkaline phosphatase released by QUANTI-Blue—Medium for detection and quantification of alkaline phosphatase.

The HEK-Blue IL-33/IL-18 cells were thawed and cultured in DMEM, 10% FCS (HI) and PEST and Normocin for two passages. After two passages the cells were cultured with selection antibiotics (Zeocin, HygroGold and Blasticidin) added to the medium above for at least one passage before the experiments, as well as during the experiments. HygroGold is required to maintain the IL-1β specificity to the cell line and Blasticidin and Zeocin are required to maintain the plasmids encoding IL1RL1 and SEAP respectively. The experiments were run on cells of 70% confluency. The cells were split 2-3 times/week, or when they had reached 80-90% confluence.

The ligands were titrated in a dose range from 30 ng/ml to 0.001 ng/ml. To generate a good assay for testing the antibodies ability to affect the IL-1 signaling (stimulate or inhibit the amount of alkaline phosphatase release) a concentration that resulted in a robust signal on the linear slope of the dose-response curve is preferred. For this system a concentration of 0.3 ng/ml of each ligand was selected. Two individual experiments were performed with individual dilution series of the antibodies. Ligands were also diluted separately for each experiment and cells from different passages were used.

Evaluation of Results

Raw data were converted to % inhibition using equation 1:
% inhibition=(1−(A−B)/(C−B))×100

• • wherein:
  • A=Ligand activity with compound dissolved in PBS added
  • B=Negative control, No Ligand, only PBS (vehicle)
  • C=Positive control, Ligand with PBS (vehicle),

IC50 represents the concentration yielding 50% inhibition of the maximal response.

EC50 represents the concentration yielding an inhibition representing 50% inhibition with respect to calculated values for the top and bottom of the curve.

Results & Conclusions

Experiments were set up elucidate the effect of two test antibodies (CAN03 and CAN01) in a reporter gene test system of HEK-Blue IL-33/IL-β cells stimulated with three different ligands (hIL-1α, hIL-1β and hIL-33) to release alkaline phosphatase. As a comparator and reference, an Isotype control was used. Cells prepared from two individual passages were used. All experiments were performed using duplicate cultures.

In a first experiment, the effect of the three different ligands on HEK-Blue IL-33/IL-p cells were evaluated to create a relevant test system. The ligands were titrated from 30 ng/ml to 0.001 ng/ml and 0.3 ng/ml was selected as an appropriate concentration for all ligands in the test system. HEK-Blue IL-33/IL-1p cells were prepared from two different passages. Cells were stimulated in the presence of 0.3 ng/ml ligands for 16 hrs, and the supernatant harvested and assessed for measuring the amount of alkaline phosphatase released.

As demonstrated in FIG. 10, CAN03 demonstrated an inhibitory effect to IL1RAP signaling by inhibiting the release of alkaline phosphatase with all ligands in the two experiments. CAN03 is able to fully inhibit IL-1α-mediated and IL-1β-mediated signaling. IL-33 induced signaling is blocked by CAN03 is to at least 95%. In contrast, CAN 01 and the isotype control did not show any inhibitory effect.

Table 5 below summarises the potency for all tested antibody candidates.

TABLE 5
IC50/EC50 (nM) mean values for the effect of CAN03,
CAN01 and Isotype control on HEK-Blue IL-33/IL-1β
cells and three different ligands (n = 2)
	Ligand IL-1α	Ligand IL-1β	Ligand IL-33
Antibody	IC50/EC50 (nM)	IC50/EC50 (nM)	IC50/EC50 (nM)
CAN03	37.34/37.60	10.08/10.46	30.40/30.51
CAN01	NA/NA	NA/NA	NA/NA
Isotype	NA/NA	NA/NA	NA/NA
control

M. In Vitro IL1RAP dependent blocking of murine IL-1α-, IL-1β- and IL-33-mediated signaling in HEK-Blue IL-33/IL-1β cells. Potency of antibodies CAN01 and CAN03.

The following experiments were performed (i) to confirm that the murine ligands can stimulate signaling through human receptor complexes, and (ii) to determine whether two exemplary antibodies (CAN01 and CAN03) were able to inhibit such signals.

Materials

Preparation of Antibodies

Exemplary antibodies of the invention (CAN01 and CAN03) together with two isotype controls (mlgG2a and hIgG1/kappa) were provided by Innovagen AB (Lund, Sweden).

All antibodies were diluted in PBS for testing. Working solutions for reporter gene assay, HEK-Blue IL-33/IL-1β were made in PBS at 20 times at the final assay concentration. The final assay volume was 200 μl (containing 10 μl antibody or diluent (PBS)+180 μl cells+10 μl ligand) Final assay concentrations of antibodies were as follows; 100 to 0.01 nM (by serial dilutions in 3-fold dilutions steps).

Preparation of Human Ligands (IL-1α, IL-1β (and IL-33)

Murine ligands, IL-1α. IL-1β and IL-33 were diluted in PBS to a stock concentration of 10 μg/mL. Stock concentrations of 10 μg/mL of the ligands were stored in aliquots at −80° C. until use. For the reporter gene assay, the ligands were used at a final concentration of 10 ng/mL for mIL-1α, 100 ng/mL for mIL-1β and 2 ng/mL for mIL-33; these concentrations gave 70-80% of the maximal effect in the assay as determined in a pre-test experiment.

Dilution of Ligands to Final Assay Concentration

(a) mIL-1α, 10 ng/mL

• • Stock of ligands 10 μg/mL was diluted 1:50 (200 μl+800 μl Selective medium, see below)=200 ng/mL
  • 200 ng/mL was diluted 1:20 in the assay; 10 μl of LPS 200 ng/mL+190 μl cells and compound/well to yield a final concentration of 10 ng/mL

(b) mIL-1β, 100 ng/mL

• • Stock of ligands 10 μg/mL was diluted 1:5 (200 μl+800 μl Selective medium, see below)=2000 ng/mL
  • 2000 ng/mL was diluted 1:20 in the assay; 10 μl of LPS 2000 ng/mL+190 μl cells and compound/well to yield a final concentration of 100 ng/mL
  • (c) mIL-33, 2 ng/mL
  • Stock of ligands 10 μg/mL was diluted 1:250 (10 μl+2490 μl Selective medium, see below)=40 ng/mL
  • 40 ng/mL was diluted 1:20 in the assay; 10 μl of LPS 200 ng/mL+190 μl cells and compound/well to yield a final concentration of 2 ng/mL

Cell Line

HEK-Blue IL-33/IL-1β cells, generated by stable transfection of HEK-Blue™ IL-1β cells with the IL1RL1, were used as IL-33/IL-1β sensor cells (Cat no. hkb-IL-33, InvivoGen, San Diego, US).

Methods

Study Design

Stock solutions of CAN01, CAN03 and the two isotype controls were prepared in PBS. Working solutions for reporter gene assay, HEK-Blue IL-33/IL-1β were made in PBS at 20 times at the final assay concentration. The final assay volume was 200 μl (containing 10 μl antibody or diluent (PBS)+180 μl cells+10 μl ligand). Final assay concentrations of antibodies were as follows; 100 to 0.01 nM (by serial dilutions in 3-fold dilutions steps. In control wells (stimulated/unstimulated cells) antibodies were replaced by 10 μl PBS.

Culturing and Stimulation of HEK-Blue IL-33/IL-1β Cells

As IL1RAP is a functional part of the IL-1 receptor complex, antibodies binding to IL1RAP have the potential to inhibit IL-1 signaling. Since tumour cells have been reported to use IL1RAP dependent ligands such as IL-1α, IL-1β and IL-33 as a growth factor, blocking this signal may provide an important mechanism for mediating anti-tumour effects (either separately or combined with an ADCC effect). In order to test for the capability of antibodies to block IL-1 signaling, an IL-1 dependent reporter gene assay was set up. HEK-Blue IL-33/IL-1 p cells (InvivoGen) respond to IL-1 signaling by the release of alkaline phosphatase that can be quantified by a colorimetric assay. To test the inhibitory capacity of the lead candidates HEK-Blue cells were plated at 50 000 cells/well and incubated with the test antibodies 45 minutes prior to stimulation with murine IL-1α, IL-1β, and IL-33 in a final concentration to give optimal stimulation. Final assay concentrations of antibodies were 100 nM-0.01 nM. In control wells, antibodies were replaced by PBS. The cells were incubated at 37° C. o/n before measuring the amount of alkaline phosphatase released by QUANTI-Blue—Medium for detection and quantification of alkaline phosphatase.

The HEK-Blue IL-33/IL-1β cells were thawed and cultured in DMEM, 10% FCS (HI) and PEST and Normocin for two passages. After two passages the cells were cultured with selection antibiotics (Zeocin, HygroGold and Blasticidin) added to the medium above for at least one passage before the experiments, as well as during the experiments. HygroGold is required to maintain the IL-1β specificity to the cell line and Blasticidin and Zeocin are required to maintain the plasmids encoding IL1RL1 and SEAP respectively. The experiments were run on cells of 70% confluency. The cells were split 2-3 times/week, or when they had reached 80-90% confluence.

The ligands were titrated in a dose range from 300 ng/ml to 0.01 ng/ml. To generate a good assay for testing the antibodies ability to affect the IL-1 signaling (stimulate or inhibit the amount of alkaline phosphatase release) a concentration that resulted in a robust signal on the linear slope of the dose-response curve is preferred. For this system a concentration of 10 ng/mL for mIL-1α, 100 ng/mL for mIL-1β and 2 ng/mL for mIL-33 were selected.

Evaluation of Results

Raw data were converted to % inhibition using equation 1:
inhibition=(1−(A−B)/(C−B))×100

• • wherein:
  • A=Ligand activity with compound dissolved in PBS added
  • B=Negative control, No Ligand, only PBS (vehicle)
  • C=Positive control, Ligand with PBS (vehicle),

IC50 represents the concentration yielding 50% inhibition of the maximal response.

EC50 represents the concentration yielding an inhibition representing 50% inhibition with respect to calculated values for the top and bottom of the curve.

Results & Conclusions

Experiments were set up elucidate the cross-reactivity of IL1RAP signaling of murine ligands towards the human receptors.

In a first set of experiments, the three murine ligands IL-1 alpha, IL-1 beta and IL-33 were tested for their ability to stimulate HEK Blue IL-33/IL-1β. All three murine ligands were able to stimulate the release of alkaline phosphatase, although with a significantly reduced effect as compared to their human equivalents.

In this first experiment, the effect of the three different ligands on HEK-Blue IL-33/IL-β cells was also evaluated, to create a relevant test system. The ligands were titrated from 100 ng/ml to 0.001 ng/ml and 10 ng/mL for mIL-1α, 100 ng/mL for mIL-1β and 2 ng/mL for mIL-33 were selected. The drop in efficacy was greatest for IL-1β (around 300-fold), and smallest for IL-33 (around 8 fold).

The effect of the test antibodies to inhibit the signal induced by the murine ligands was subsequently tested (see FIG. 11). As a comparison and reference, two isotype control antibodies were used (Human IgG1 and murine IgG2a). HEK-Blue IL-33/IL-1β cells were prepared. Cells were stimulated in the presence of ligands for 16 hrs, and the supernatant harvested and assessed for measuring the amount of alkaline phosphatase released. Cells prepared from two individual passages were used. All experiments were conducted using duplicate cultures.

CAN03 inhibited IL1RAP-dependent signaling mediated by all three murine ligands, as determined by release of alkaline phosphatase. CAN01 had only a limited inhibitory effect on IL1RAP-dependent signaling. None of the isotype controls showed any inhibitory effect. Due to the lack of plateau at the top of the curve for ligands IL-1β and IL-33, no IC50 and EC50 values could be calculated for CAN01.

Table 6 below summarises the potency for all tested antibody candidates.

TABLE 6
IC50/EC50 (nM) mean values for the effect of CAN01, CAN03, Mouse
IgG2a (Isotype control) and Human IgG1/kappa (Isotype control) (n = 1)
	Ligand IL-1 alpha	Ligand IL-1 beta	Ligand IL-33
Antibody	IC50/EC50 (nM)	IC50/EC50 (nM)	IC50/EC50 (nM)
CAN01	81.71/84.17	50.04/>100	>100/>100
CAN03	5.0/2.90	1.59/1.56	4.12/4.01
Mouse IgG2a,	NA/NA	NA/NA	NA/NA
Isotype control
Human IgG1,	NA/NA	NA/NA	NA/NA
Isotype control

Example N—Analysis of Competitive Binding by ELISA

Protocol

• • All samples should be analysed in duplicate.
  • Coat a Nunc-MaxiSorp 96 Micro Well™ Plate with 100 μl/well of recombinant hIL1RAP 21-367 (1 μg/ml) diluted in 0.01M PBS, pH 7.4.
  • Incubate the plate overnight at 4° C.
  • Wash the plate with ELISA washing buffer (0.01M PBS, 0.05% Tween 20, pH 7.4).
  • Add 150 μl/well of ELISA blocking solution (PBS, 0.5% BSA, 0.05% Tween 20, pH 7.4).
  • Incubate the plate for 1 h at room temperature (RT) under agitation.
  • Wash the plate with ELISA washing buffer.
  • Add samples of test items (e.g. mAb 1, mAb 2) to wells (100 μl/well, 10 μg/ml)
  • Incubate the plate for 1 h at RT.
  • Wash the plate with ELISA washing solution.
  • Add a solution of reference antibody, such as CAN01 or CAN03 (100 μl/well, 1 μg/ml) to all wells.
  • Incubate the plate for 1 h at RT.
  • Wash the plate with ELISA washing buffer.
  • Add 100 μl/well of a suitable secondary antibody conjugated to Alkaline rabbit anti-mouse IgG conjugated to Alkaline Phosphatase (If the test items are human antibodies, a suitable secondary antibody would be Goat Anti-Mouse IgG (Fc specific)—Alkaline Phosphatase antibody, SIGMA, A1418)
  • Incubate the plate for 1 h at RT under agitation.
  • Wash the plate with washing buffer.
  • Add 100 μl of pNPP substrate per well. (4-Nitrophenyl phosphatase disodium salt hexahydrate, SIGMA, 1 mg/ml).
  • Incubate the plate at RT under agitation and measure absorbance at 405 nm consecutively for 30 min. Absorbance at 0 min should be taken as background signal.

Claims

1. A method for detecting cells expressing IL1RAP, the method comprising:

(a) contacting cells with an antibody comprising the following complementary determining regions (CDRs): i. Heavy chain CDR1 comprising: G F T F S I Y (SEQ ID NO: 21); ii. Heavy chain CDR2 comprising: S I G G S Y (SEQ ID NO: 22); iii. Heavy chain CDR3 comprising: E V D G S Y A M D Y (SEQ ID NO: 23); iv. Light chain CDR 1 comprising: R A S Q S I G T S I H (SEQ ID NO: 26); v. Light chain CDR2 comprising: S A S E S I S (SEQ ID NO: 27); and vi. Light chain CDR3 comprising: Q Q S N S W P T T (SEQ ID NO: 28); and

(b) detecting binding of the antibody to the cells.

2. The method of claim 1, wherein the cells are from a human subject.

3. The method of claim 1 wherein the detecting is in vivo.

4. The method of claim 1 wherein the detecting is ex vivo.

5. The method of claim 1, wherein the cells are associated with a neoplastic disorder.

6. The method of claim 5, wherein the neoplastic disorder is a neoplastic hematologic disorder.

7. The method of claim 6, wherein the neoplastic hematologic disorder is selected from chronic myeloid leukemia (CML), myeloproliferative disorders (MPD), myelodysplastic syndrome (MDS), acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML).

8. The method of claim 6, wherein the neoplastic disorder is associated with the formation of solid tumors within the subject's body.

9. The method of claim 8, wherein the solid tumor is selected from prostate cancer, breast cancer, lung cancer, colorectal cancer, melanomas, bladder cancer, brain/CNS cancer, cervical cancer, oesophageal cancer, gastric cancer, head/neck cancer, kidney cancer, liver cancer, lymphomas, ovarian cancer, pancreatic cancer, and sarcomas.

10. The method of claim 1, wherein heavy chain CDR1 of the antibody comprises: G F T F S I Y T M S (SEQ ID NO: 24) and wherein heavy chain CDR2 of the antibody comprises: T I S I G G S Y I N Y P D S V K G (SEQ ID NO: 25).

11. The method of claim 1, wherein the antibody is an Fv fragment or an Fab fragment.

12. The method of claim 1, wherein the antibody comprises a heavy chain variable region comprising or consisting of the amino acids of SEQ ID NO: 19.

13. The method of claim 1, wherein the antibody comprises a light chain variable region comprising or consisting of the amino acids of SEQ ID NO: 20.

14. The method of claim 1, wherein the antibody comprises a heavy chain variable region comprising or consisting of amino acids of SEQ ID NO: 19, and a light chain variable region comprising or consisting of the amino acids of SEQ ID NO: 20.

15. The method of claim 1, wherein the antibody comprises an Fc region.

16. The method of claim 1, wherein the antibody comprises a detectable moiety.

17. The method of claim 16, wherein the detectable moiety comprises a radioisotope, paramagnetic isotope, or a cytotoxic moiety.